X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=hardware%2Fgmc-mh-1x-2x%2Fprotocol.c;h=ceb138e965c0936467e10f8f9390a3abaeff4f61;hb=ecaa89af0e01f9c3f585e82eb849bf616bff22cf;hp=ef7427fe914c75f696a3de9aa2df1076cd0b412c;hpb=7b4edcb654d6b36da4369bac3688ad77f6132766;p=libsigrok.git

diff --git a/hardware/gmc-mh-1x-2x/protocol.c b/hardware/gmc-mh-1x-2x/protocol.c
index ef7427fe..ceb138e9 100644
--- a/hardware/gmc-mh-1x-2x/protocol.c
+++ b/hardware/gmc-mh-1x-2x/protocol.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the libsigrok project.
  *
- * Copyright (C) 2013 Matthias Heidbrink <m-sigrok@heidbrink.biz>
+ * Copyright (C) 2013, 2014 Matthias Heidbrink <m-sigrok@heidbrink.biz>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -17,12 +17,1161 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/** @file
+ *  Gossen Metrawatt Metrahit 1x/2x drivers
+ *  @internal
+ */
+
+#include <math.h>
+#include <string.h>
 #include "protocol.h"
 
+/* Internal Headers */
+static guchar calc_chksum_14(guchar* dta);
+static int chk_msg14(struct sr_dev_inst *sdi);
+
+/** Set or clear flags in devc->mqflags. */
+static void setmqf(struct dev_context *devc, uint64_t flags, gboolean set)
+{
+	if (set)
+		devc->mqflags |= flags;
+	else
+		devc->mqflags &= ~flags;
+}
+
+/** Decode current type and measured value, Metrahit 12-16. */
+static void decode_ctmv_16(uint8_t ctmv, struct dev_context *devc)
+{
+	devc->mq = 0;
+	devc->unit = 0;
+	devc->mqflags = 0;
+
+	switch (ctmv) {
+	case 0x00: /* 0000 - */
+		break;
+	case 0x01: /* 0001 mV DC */
+		devc->scale1000 = -1; /* Fall through */
+	case 0x02: /* 0010 V DC */
+	case 0x03: /* 0011 V AC+DC */
+	case 0x04: /* 0100 V AC */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_VOLT;
+		if (ctmv <= 0x03)
+			devc->mqflags |= SR_MQFLAG_DC;
+		if (ctmv >= 0x03) {
+			devc->mqflags |= SR_MQFLAG_AC;
+			if (devc->model >= METRAHIT_16S)
+				devc->mqflags |= SR_MQFLAG_RMS;
+		}
+		break;
+	case 0x05: /* 0101 Hz (15S/16S only) */
+	case 0x06: /* 0110 kHz (15S/16S only) */
+		devc->mq = SR_MQ_FREQUENCY;
+		devc->unit = SR_UNIT_HERTZ;
+		if (ctmv == 0x06)
+			devc->scale1000 = 1;
+		break;
+	case 0x07: /* 0111 % (15S/16S only) */
+		devc->mq = SR_MQ_DUTY_CYCLE;
+		devc->unit = SR_UNIT_PERCENTAGE;
+		break;
+	case 0x08: /* 1000 Diode */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_VOLT;
+		devc->mqflags |= SR_MQFLAG_DIODE;
+		break;
+	case 0x09: /* 1001 Ohm, °C */
+	case 0x0a: /* 1010 kOhm */
+	case 0x0b: /* 1011 MOhm */
+		devc->mq = SR_MQ_RESISTANCE; /* Changed to temp. later if req.*/
+		devc->unit = SR_UNIT_OHM;
+		devc->scale1000 = ctmv - 0x09;
+		break;
+	case 0x0c: /* 1100 nF (15S/16S only) */
+	case 0x0d: /* 1101 µF (15S/16S only) */
+		devc->mq = SR_MQ_CAPACITANCE;
+		devc->unit = SR_UNIT_FARAD;
+		if (ctmv == 0x0c)
+			devc->scale1000 = -3;
+		else
+			devc->scale1000 = -2;
+		break;
+	case 0x0e: /* mA, µA */
+		devc->scale1000 = -1; /* Fall through. */
+	case 0x0f: /* A */
+		devc->mq = SR_MQ_CURRENT;
+		devc->unit = SR_UNIT_AMPERE;
+		if (devc->model == METRAHIT_16S)
+			devc->mqflags |= SR_MQFLAG_RMS;
+		/* 16I A only with clamp, RMS questionable. */
+		break;
+	}
+}
+
+/**
+ * Decode range/sign/acdc byte special chars (Metrahit 12-16).
+ *
+ * @param[in] rs Range and sign byte.
+ */
+static void decode_rs_16(uint8_t rs, struct dev_context *devc)
+{
+	sr_spew("decode_rs_16(%d) scale = %f", rs, devc->scale);
+
+	if (rs & 0x04) /* Sign */
+		devc->scale *= -1.0;
+
+	if (devc->mq == SR_MQ_CURRENT) {
+		if (rs & 0x08) /* Current is AC */
+			devc->mqflags |= SR_MQFLAG_AC;
+		else
+			devc->mqflags |= SR_MQFLAG_DC;
+	}
+
+	switch (rs & 0x03) {
+	case 0:
+		if (devc->mq == SR_MQ_VOLTAGE) /* V */
+			devc->scale *= 0.1;
+		else if (devc->mq == SR_MQ_CURRENT) /* 000.0 µA */
+			devc->scale *= 0.0000001; /* Untested! */
+		else if (devc->mq == SR_MQ_RESISTANCE) {
+			if (devc->buflen >= 10) {
+				/* °C with 10 byte msg type, otherwise GOhm. */
+				devc->mq = SR_MQ_TEMPERATURE;
+				devc->unit = SR_UNIT_CELSIUS;
+				devc->scale *= 0.01;
+			} else if (devc->scale1000 == 2) {
+				/* 16I Iso 500/1000V 3 GOhm */
+				devc->scale *= 0.1;
+			}
+		}
+		break;
+	case 1:
+		devc->scale *= 0.0001;
+		break;
+	case 2:
+		devc->scale *= 0.001;
+		break;
+	case 3:
+		devc->scale *= 0.01;
+		break;
+	}
+}
+
+/**
+ * Decode special chars, Metrahit 12-16.
+ *
+ * @param[in] spc Special characters 1 and 2 (s1 | (s2 << 4)).
+ */
+static void decode_spc_16(uint8_t spc, struct dev_context *devc)
+{
+	/* xxxx1xxx ON */
+	/* TODO: What does that mean? Power on? The 16I sets this. */
+	/* xxxxx1xx BEEP */
+	/* xxxxxx1x Low battery */
+	/* xxxxxxx1 FUSE */
+	/* 1xxxxxxx MIN */
+	setmqf(devc, SR_MQFLAG_MIN, spc & 0x80);
+
+	/* x1xxxxxx MAN */
+	setmqf(devc, SR_MQFLAG_AUTORANGE, !(spc & 0x40));
+
+	/* xx1xxxxx DATA */
+	setmqf(devc, SR_MQFLAG_HOLD, spc & 0x20);
+
+	/* xxx1xxxx MAX */
+	setmqf(devc, SR_MQFLAG_MAX, spc & 0x10);
+}
+
+/** Decode current type and measured value, Metrahit 18. */
+static void decode_ctmv_18(uint8_t ctmv, struct dev_context *devc)
+{
+	devc->mq = 0;
+	devc->unit = 0;
+	devc->mqflags = 0;
+
+	switch (ctmv) {
+	case 0x00: /* 0000 - */
+		break;
+	case 0x01: /* 0001 V AC */
+	case 0x02: /* 0010 V AC+DC */
+	case 0x03: /* 0011 V DC */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_VOLT;
+		if (ctmv <= 0x02)
+			devc->mqflags |= (SR_MQFLAG_AC | SR_MQFLAG_RMS);
+		if (ctmv >= 0x02)
+			devc->mqflags |= SR_MQFLAG_DC;
+		break;
+	case 0x04: /* 0100 Ohm/Ohm with buzzer */
+		devc->mq = SR_MQ_RESISTANCE;
+		devc->unit = SR_UNIT_OHM;
+		break;
+	case 0x05: /* 0101 Diode/Diode with buzzer */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_VOLT;
+		devc->mqflags |= SR_MQFLAG_DIODE;
+		break;
+	case 0x06: /* 0110 °C */
+		devc->mq = SR_MQ_TEMPERATURE;
+		devc->unit = SR_UNIT_CELSIUS;
+		break;
+	case 0x07: /* 0111 F */
+		devc->mq = SR_MQ_CAPACITANCE;
+		devc->unit = SR_UNIT_FARAD;
+		break;
+	case 0x08: /* 1000 mA DC */
+	case 0x09: /* 1001 A DC */
+	case 0x0a: /* 1010 mA AC+DC */
+	case 0x0b: /* 1011 A AC+DC */
+		devc->mq = SR_MQ_CURRENT;
+		devc->unit = SR_UNIT_AMPERE;
+		devc->mqflags |= SR_MQFLAG_DC;
+		if (ctmv >= 0x0a)
+			devc->mqflags |= (SR_MQFLAG_AC | SR_MQFLAG_RMS);
+		if ((ctmv == 0x08) || (ctmv == 0x0a))
+			devc->scale1000 = -1;
+		break;
+	case 0x0c: /* 1100 Hz */
+		devc->mq = SR_MQ_FREQUENCY;
+		devc->unit = SR_UNIT_HERTZ;
+		break;
+	case 0x0d: /* 1101 dB */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_DECIBEL_VOLT;
+		devc->mqflags |= SR_MQFLAG_AC; /* dB available for AC only */
+		break;
+	case 0x0e: /* 1110 Events AC, Events AC+DC. Actually delivers just
+		* current voltage via IR, nothing more. */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_VOLT;
+		devc->mqflags |= SR_MQFLAG_AC | SR_MQFLAG_DC | SR_MQFLAG_RMS;
+		break;
+	case 0x0f: /* 1111 Clock */
+		devc->mq = SR_MQ_TIME;
+		devc->unit = SR_UNIT_SECOND;
+		devc->mqflags |= SR_MQFLAG_DURATION;
+		break;
+	}
+}
+
+/**
+ * Decode range/sign/acdc byte special chars, Metrahit 18.
+ *
+ * @param[in] rs Rance/sign byte.
+ */
+static void decode_rs_18(uint8_t rs, struct dev_context *devc)
+{
+	int range;
+
+	/* Sign */
+	if (((devc->scale > 0) && (rs & 0x08)) ||
+			((devc->scale < 0) && !(rs & 0x08)))
+		devc->scale *= -1.0;
+
+	/* Range */
+	range = rs & 0x07;
+	switch (devc->mq) {
+	case SR_MQ_VOLTAGE:
+		if (devc->unit == SR_UNIT_DECIBEL_VOLT) {
+			devc->scale *= pow(10.0, -2);
+			/*
+			 * When entering relative mode, the device switches
+			 * from 10 byte to 6 byte msg format. Unfortunately
+			 * it switches back to 10 byte when the second value
+			 * is measured, so that's not sufficient to
+			 * identify relative mode.
+			 */
+		}
+		else if (devc->vmains_29S)
+			devc->scale *= pow(10.0, range - 2);
+		else
+			devc->scale *= pow(10.0, range - 5);
+		break;
+	case SR_MQ_CURRENT:
+		if (devc->scale1000 == -1)
+			devc->scale *= pow(10.0, range - 5);
+		else
+			devc->scale *= pow(10.0, range - 4);
+		break;
+	case SR_MQ_RESISTANCE:
+		devc->scale *= pow(10.0, range - 2);
+		break;
+	case SR_MQ_FREQUENCY:
+		devc->scale *= pow(10.0, range - 2);
+		break;
+	case SR_MQ_TEMPERATURE:
+		devc->scale *= pow(10.0, range - 2);
+		break;
+	case SR_MQ_CAPACITANCE:
+		devc->scale *= pow(10.0, range - 13);
+		break;
+		/* TODO: 29S Mains measurements. */
+	}
+}
+
+/**
+ * Decode special chars, Metrahit 18.
+ *
+ * @param[in] spc Special characters 1 and 2 (s1 | (s2 << 4)).
+ */
+static void decode_spc_18(uint8_t spc, struct dev_context *devc)
+{
+	/* xxxx1xxx ZERO */
+	/* xxxxx1xx BEEP */
+	/* xxxxxx1x Low battery */
+	/* xxxxxxx1 Fuse */
+
+	if (devc->mq == SR_MQ_TIME) {
+		/* xxx1xxxx Clock running: 1; stop: 0 */
+		sr_spew("Clock running: %d", spc >> 4);
+	} else {
+		/* 1xxxxxxx MAN */
+		setmqf(devc, SR_MQFLAG_AUTORANGE, !(spc & 0x80));
+
+		/* x1xxxxxx MIN */
+		setmqf(devc, SR_MQFLAG_MIN, spc & 0x40);
+
+		/* xx1xxxxx MAX */
+		setmqf(devc, SR_MQFLAG_MAX, spc & 0x20);
+
+		/* xxx1xxxx DATA */
+		setmqf(devc, SR_MQFLAG_HOLD, spc & 0x10);
+	}
+}
+
+/**
+ * Decode current type and measured value, Metrahit 2x.
+ *
+ * @param[in] ctmv Current type and measured value (v1 | (v2 << 4)).
+ */
+static void decode_ctmv_2x(uint8_t ctmv, struct dev_context *devc)
+{
+	if ((ctmv > 0x1c) || (!devc)) {
+		sr_err("decode_ctmv_2x(%d): invalid param(s)!", ctmv);
+		return;
+	}
+
+	devc->mq = 0;
+	devc->unit = 0;
+	devc->mqflags = 0;
+
+	switch (ctmv) {
+	/* 00000 unused */
+	case 0x01: /* 00001 V DC */
+	case 0x02: /* 00010 V AC+DC */
+	case 0x03: /* 00011 V AC */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_VOLT;
+		if (ctmv <= 0x02)
+			devc->mqflags |= SR_MQFLAG_DC;
+		if (ctmv >= 0x02) {
+			devc->mqflags |= SR_MQFLAG_AC;
+			if (devc->model >= METRAHIT_24S)
+				devc->mqflags |= SR_MQFLAG_RMS;
+		}
+		break;
+	case 0x04: /* 00100 mA DC */
+	case 0x05: /* 00101 mA AC+DC */
+		devc->scale1000 = -1;
+	case 0x06: /* 00110 A DC */
+	case 0x07: /* 00111 A AC+DC */
+		devc->mq = SR_MQ_CURRENT;
+		devc->unit = SR_UNIT_AMPERE;
+		devc->mqflags |= SR_MQFLAG_DC;
+		if ((ctmv == 0x05) || (ctmv == 0x07)) {
+			devc->mqflags |= SR_MQFLAG_AC;
+			if (devc->model >= METRAHIT_24S)
+				devc->mqflags |= SR_MQFLAG_RMS;
+		}
+		break;
+	case 0x08: /* 01000 Ohm */
+		devc->mq = SR_MQ_RESISTANCE;
+		devc->unit = SR_UNIT_OHM;
+		break;
+	case 0x09: /* 01001 F */
+		devc->mq = SR_MQ_CAPACITANCE;
+		devc->unit = SR_UNIT_FARAD;
+		devc->scale *= 0.1;
+		break;
+	case 0x0a: /* 01010 V dB */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_DECIBEL_VOLT;
+		devc->mqflags |= SR_MQFLAG_AC;
+		if (devc->model >= METRAHIT_24S)
+			devc->mqflags |= SR_MQFLAG_RMS;
+		break;
+	case 0x0b: /* 01011 Hz U ACDC */
+	case 0x0c: /* 01100 Hz U AC */
+		devc->mq = SR_MQ_FREQUENCY;
+		devc->unit = SR_UNIT_HERTZ;
+		devc->mqflags |= SR_MQFLAG_AC;
+		if (ctmv <= 0x0b)
+			devc->mqflags |= SR_MQFLAG_DC;
+		break;
+	case 0x0d: /* 01101 W on power, mA range (29S only) */
+		devc->scale *= 0.001;
+		/* Fall through! */
+	case 0x0e: /* 01110 W on power, A range (29S only) */
+		devc->mq = SR_MQ_POWER;
+		devc->unit = SR_UNIT_WATT;
+		break;
+	case 0x0f: /* 01111 Diode */
+	case 0x10: /* 10000 Diode with buzzer (actually cont. with voltage) */
+		devc->unit = SR_UNIT_VOLT;
+		if (ctmv == 0x0f) {
+			devc->mq = SR_MQ_VOLTAGE;
+			devc->mqflags |= SR_MQFLAG_DIODE;
+		} else {
+			devc->mq = SR_MQ_CONTINUITY;
+			devc->scale *= 0.00001;
+		}
+		devc->unit = SR_UNIT_VOLT;
+		break;
+	case 0x11: /* 10001 Ohm with buzzer */
+		devc->mq = SR_MQ_CONTINUITY;
+		devc->unit = SR_UNIT_OHM;
+		devc->scale1000 = -1;
+		break;
+	case 0x12: /* 10010 Temperature */
+		devc->mq = SR_MQ_TEMPERATURE;
+		devc->unit = SR_UNIT_CELSIUS;
+		/* This can be Fahrenheit. That is detected by range=4 later. */
+		break;
+	/* 0x13 10011, 0x14 10100 unsed */
+	case 0x15: /* 10101 Press (29S only) */
+		/* TODO: What does that mean? Possibly phase shift?
+		   Then we need a unit/flag for it. */
+		devc->mq = SR_MQ_GAIN;
+		devc->unit = SR_UNIT_PERCENTAGE;
+		break;
+	case 0x16: /* 10110 Pulse W (29S only) */
+		/* TODO: Own unit and flag for this! */
+		devc->mq = SR_MQ_POWER;
+		devc->unit = SR_UNIT_WATT;
+		break;
+	case 0x17: /* 10111 TRMS V on mains (29S only) */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_VOLT;
+		devc->mqflags |= (SR_MQFLAG_AC | SR_MQFLAG_RMS);
+		devc->vmains_29S = TRUE;
+		break;
+	case 0x18: /* 11000 Counter (zero crossings of a signal) */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_UNITLESS;
+		break;
+	case 0x19: /* 11001 Events U ACDC */
+	case 0x1a: /* 11010 Events U AC */
+		/* TODO: No unit or flags for this yet! */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_UNITLESS;
+		devc->mqflags |= SR_MQFLAG_AC;
+		if (ctmv <= 0x19)
+			devc->mqflags |= SR_MQFLAG_DC;
+		break;
+	case 0x1b: /* 11011 pulse on mains (29S only) */
+		/* TODO: No unit or flags for this yet! */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_UNITLESS;
+		devc->mqflags |= SR_MQFLAG_AC;
+		break;
+	case 0x1c: /* 11100 dropout on mains (29S only) */
+		/* TODO: No unit or flags for this yet! */
+		devc->mq = SR_MQ_VOLTAGE;
+		devc->unit = SR_UNIT_UNITLESS;
+		devc->mqflags |= SR_MQFLAG_AC;
+		break;
+	default:
+		sr_err("decode_ctmv_2x(%d, ...): Unknown ctmv!");
+		break;
+	}
+}
+
+/**
+ * Decode range/sign/acdc byte special chars, Metrahit 2x, table TR.
+ *
+ * @param[in] rs Range/sign byte.
+ */
+static void decode_rs_2x(uint8_t rs, struct dev_context *devc)
+{
+	int range;
+
+	/* Sign */
+	if (((devc->scale > 0) && (rs & 0x08)) ||
+			((devc->scale < 0) && !(rs & 0x08)))
+		devc->scale *= -1.0;
+
+	/* Range */
+	range = rs & 0x07;
+	switch (devc->mq) {
+	case SR_MQ_VOLTAGE:
+		if (devc->unit == SR_UNIT_DECIBEL_VOLT)
+			devc->scale *= pow(10.0, -3);
+		else if (devc->vmains_29S)
+			devc->scale *= pow(10.0, range - 2);
+		else
+			devc->scale *= pow(10.0, range - 6);
+		break;
+	case SR_MQ_CURRENT:
+		if (devc->scale1000 != -1) /* uA, mA */
+			range += 1;/* mA and A ranges differ by 10^4, not 10^3!*/
+		devc->scale *= pow(10.0, range - 6);
+		break;
+	case SR_MQ_RESISTANCE:
+		devc->scale *= pow(10.0, range - 3);
+		break;
+	case SR_MQ_FREQUENCY:
+		devc->scale *= pow(10.0, range - 3);
+		break;
+	case SR_MQ_TEMPERATURE:
+		if (range == 4) /* Indicator for °F */
+			devc->unit = SR_UNIT_FAHRENHEIT;
+		devc->scale *= pow(10.0, - 2);
+		break;
+	case SR_MQ_CAPACITANCE:
+		if (range == 7)
+			range -= 1; /* Same value as range 6 */
+		devc->scale *= pow(10.0, range - 13);
+		break;
+	/* TODO: 29S Mains measurements. */
+	}
+}
+
+/**
+ * Decode range/sign/acdc byte special chars, Metrahit 2x, table TR 2.
+ *
+ * @param[in] rs Range/sign byte.
+ */
+static void decode_rs_2x_TR2(uint8_t rs, struct dev_context *devc)
+{
+	int range;
+
+	/* Range */
+	range = rs & 0x07;
+	switch (devc->mq) {
+	case SR_MQ_CURRENT:
+		if (devc->scale1000 == -1) /* mA */
+			switch(range) {
+			case 0: case 1:	/* 100, 300 µA */
+				devc->scale *= pow(10.0, -6);
+				break;
+			case 2: case 3:	/* 1, 3 mA */
+				devc->scale *= pow(10.0, -5);
+				break;
+			case 4: case 5:	/* 10, 30 mA */
+				devc->scale *= pow(10.0, -4);
+				break;
+			case 6: case 7:	/* 100, 300 mA */
+				devc->scale *= pow(10.0, -3);
+				break;
+			}
+		else /* A */
+			switch(range) {
+			case 0: case 1:	/* 1, 3 A */
+				devc->scale *= pow(10.0, -5);
+				break;
+			case 2: /* 10 A */
+				devc->scale *= pow(10.0, -4);
+				break;
+			}
+		break;
+	default:
+		decode_rs_2x(rs, devc);
+		return;
+	}
+
+	/* Sign */
+	if (((devc->scale > 0) && (rs & 0x08)) ||
+			((devc->scale < 0) && !(rs & 0x08)))
+		devc->scale *= -1.0;
+}
+
+
+/**
+ * Decode special chars (Metrahit 2x).
+ *
+ * @param[in] spc Special characters 1 and 2 (s1 | (s2 << 4)).
+ */
+static void decode_spc_2x(uint8_t spc, struct dev_context *devc)
+{
+	/* xxxxxxx1 Fuse */
+
+	/* xxxxxx1x Low battery */
+
+	/* xxxxx1xx BEEP */
+
+	/* xxxx1xxx ZERO */
+
+	/* xxx1xxxx DATA */
+	setmqf(devc, SR_MQFLAG_HOLD, spc & 0x10);
+
+	/* x11xxxxx unused */
+	/* 1xxxxxxx MAN */
+	setmqf(devc, SR_MQFLAG_AUTORANGE, !(spc & 0x80));
+}
+
+/** Clean range and sign. */
+static void clean_rs_v(struct dev_context *devc)
+{
+	devc->value = 0.0;
+	devc->scale = 1.0;
+}
+
+/** Clean current type, measured variable, range and sign. */
+static void clean_ctmv_rs_v(struct dev_context *devc)
+{
+	devc->mq = 0;
+	devc->unit = 0;
+	devc->mqflags = 0;
+	devc->scale1000 = 0;
+	devc->vmains_29S = FALSE;
+	clean_rs_v(devc);
+}
+
+/** Send prepared value. */
+static void send_value(struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	struct sr_datafeed_analog analog;
+	struct sr_datafeed_packet packet;
+
+	devc = sdi->priv;
+
+	memset(&analog, 0, sizeof(analog));
+	analog.probes = sdi->probes;
+	analog.num_samples = 1;
+	analog.mq = devc->mq;
+	analog.unit = devc->unit;
+	analog.mqflags = devc->mqflags;
+	analog.data = &devc->value;
+
+	memset(&packet, 0, sizeof(packet));
+	packet.type = SR_DF_ANALOG;
+	packet.payload = &analog;
+	sr_session_send(devc->cb_data, &packet);
+
+	devc->num_samples++;
+}
+
+/** Process 6-byte data message, Metrahit 1x/2x send mode. */
+static void process_msg_dta_6(struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	int cnt;
+	uint8_t dgt;
+
+	devc = sdi->priv;
+	clean_rs_v(devc);
+
+	/* Byte 0, range and sign */
+	if (devc->model <= METRAHIT_16X)
+		decode_rs_16(bc(devc->buf[0]), devc);
+	else if (devc->model < METRAHIT_2X)
+		decode_rs_18(bc(devc->buf[0]), devc);
+	else {
+		decode_rs_2x(bc(devc->buf[0]), devc);
+		devc->scale *= 10; /* Compensate for format having only 5 digits, decode_rs_2x() assumes 6. */
+	}
+
+	/* Bytes 1-5, digits (ls first). */
+	for (cnt = 0; cnt < 5; cnt++) {
+		dgt = bc(devc->buf[1 + cnt]);
+		if (dgt >= 10) {
+			/* 10 Overload; on model <= 16X also 11 possible. */
+			devc->value = NAN;
+			devc->scale = 1.0;
+			break;
+		}
+		devc->value += pow(10.0, cnt) * dgt;
+	}
+
+	sr_spew("process_msg_dta_6() value=%f scale=%f scale1000=%d",
+		devc->value, devc->scale, devc->scale1000);
+	if (devc->value != NAN)
+		devc->value *= devc->scale * pow(1000.0, devc->scale1000);
+
+	/* Create and send packet. */
+	send_value(sdi);
+}
+
+/** Process 5-byte info message, Metrahit 1x/2x. */
+static void process_msg_inf_5(struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	enum model model;
+
+	devc = sdi->priv;
+
+	clean_ctmv_rs_v(devc);
+
+	/* Process byte 0 */
+	model = gmc_decode_model_sm(bc(devc->buf[0]));
+	if (model != devc->model) {
+		sr_warn("Model mismatch in data: Detected %s, now %s",
+			gmc_model_str(devc->model), gmc_model_str(model));
+	}
+
+	/* Process bytes 1-4 */
+	if (devc->model <= METRAHIT_16X) {
+		decode_ctmv_16(bc(devc->buf[1]), devc);
+		decode_spc_16(bc(devc->buf[2]) | (bc(devc->buf[3]) << 4), devc);
+		decode_rs_16(bc(devc->buf[4]), devc);
+	} else if (devc->model <= METRAHIT_18S) {
+		decode_ctmv_18(bc(devc->buf[1]), devc);
+		decode_spc_18(bc(devc->buf[2]) | (bc(devc->buf[3]) << 4), devc);
+		decode_rs_18(bc(devc->buf[4]), devc);
+	} else { /* Must be Metrahit 2x */
+		decode_ctmv_2x(bc(devc->buf[1]), devc);
+		decode_spc_2x(bc(devc->buf[2]) | (bc(devc->buf[3]) << 4), devc);
+		decode_rs_2x(bc(devc->buf[4]), devc);
+	}
+}
+
+/** Process 10-byte info/data message, Metrahit 15+. */
+static void process_msg_inf_10(struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	int cnt;
+	uint8_t dgt;
+
+	devc = sdi->priv;
+
+	process_msg_inf_5(sdi);
+
+	/* Now decode numbers */
+	for (cnt = 0; cnt < 5; cnt++) {
+		dgt = bc(devc->buf[5 + cnt]);
+		if (dgt == 11) { /* Empty digit */
+			dgt = 0;
+		}
+		else if (dgt >= 12) { /* Overload */
+			devc->value = NAN;
+			devc->scale = 1.0;
+			break;
+		}
+		devc->value += pow(10.0, cnt) * dgt;
+	}
+	sr_spew("process_msg_inf_10() value=%f scale=%f scalet=%d",
+		devc->value, devc->scale,  devc->scale1000);
+
+	if (devc->value != NAN)
+		devc->value *= devc->scale * pow(1000.0, devc->scale1000);
+
+	/* Create and send packet. */
+	send_value(sdi);
+}
+
+/** Decode send interval (Metrahit 2x only). */
+static const char *decode_send_interval(uint8_t si)
+{
+	switch (si) {
+	case 0x00:
+		return "0.05";
+	case 0x01:
+		return "0.1";
+	case 0x02:
+		return "0.2";
+	case 0x03:
+		return "0.5";
+	case 0x04:
+		return "00:01";
+	case 0x05:
+		return "00:02";
+	case 0x06:
+		return "00:05";
+	case 0x07:
+		return "00:10";
+	case 0x08:
+		return "00:20";
+	case 0x09:
+		return "00:30";
+	case 0x0a:
+		return "01:00";
+	case 0x0b:
+		return "02:00";
+	case 0x0c:
+		return "05:00";
+	case 0x0d:
+		return "10:00";
+	case 0x0e:
+		return "----";
+	case 0x0f:
+		return "data";
+	default:
+		return "Unknown value";
+	}
+}
+
+/** Process 13-byte info/data message, Metrahit 2x. */
+static void process_msg_inf_13(struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	enum model model;
+	int cnt;
+	uint8_t dgt;
+
+	devc = sdi->priv;
+
+	clean_ctmv_rs_v(devc);
+
+	/* Byte 0, model. */
+	model = gmc_decode_model_sm(bc(devc->buf[0]));
+	if (model != devc->model) {
+		sr_warn("Model mismatch in data: Detected %s, now %s",
+			gmc_model_str(devc->model), gmc_model_str(model));
+	}
+
+	/* Bytes 1-4, 11. */
+	decode_ctmv_2x(bc(devc->buf[1]) | (bc(devc->buf[11]) << 4), devc);
+	decode_spc_2x(bc(devc->buf[2]) | (bc(devc->buf[3]) << 4), devc);
+	decode_rs_2x(bc(devc->buf[4]), devc);
+
+	/* Bytes 5-10, digits (ls first). */
+	for (cnt = 0; cnt < 6; cnt++) {
+		dgt = bc(devc->buf[5 + cnt]);
+		if (dgt == 10) { /* Overload */
+			devc->value = NAN;
+			devc->scale = 1.0;
+			break;
+		}
+		devc->value += pow(10.0, cnt) * dgt;
+	}
+	sr_spew("process_msg_inf_13() value=%f scale=%f scale1000=%d mq=%d "
+		"unit=%d mqflags=0x%02llx", devc->value, devc->scale,
+		devc->scale1000, devc->mq, devc->unit, devc->mqflags);
+	if (devc->value != NAN)
+		devc->value *= devc->scale * pow(1000.0, devc->scale1000);
+
+	/* Byte 12, Send Interval */
+	sr_spew("Send interval: %s", decode_send_interval(bc(devc->buf[12])));
+
+	/* Create and send packet. */
+	send_value(sdi);
+}
+
+/** Dump contents of 14-byte message.
+ *  @param buf Pointer to array of 14 data bytes.
+ *  @param[in] raw Write only data bytes, no interpretation.
+ */
+void dump_msg14(guchar* buf, gboolean raw)
+{
+	if (!buf)
+		return;
+
+	if (raw)
+		sr_spew("msg14: 0x %02x %02x %02x %02x %02x %02x %02x %02x "
+			"%02x %02x %02x %02x %02x %02x",
+			buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
+				buf[7], buf[8], buf[9], buf[10], buf[11], buf[12],
+				buf[13]);
+	else
+		sr_spew("msg14: 0x a=%d c1=%02x c2=%02x cmd=%02x dta=%02x "
+			"%02x %02x %02x %02x %02x %02x %02x %02x chs=%02x",
+			buf[1] == 0x2b?buf[0] >> 2:buf[0] % 0x0f, buf[1], buf[2], buf[3], buf[4], buf[5],
+				buf[6],	buf[7], buf[8], buf[9], buf[10], buf[11],
+				buf[12], buf[13]);
+}
+
+/** Calc checksum for 14 byte message type.
+ *
+ *  @param[in] dta Pointer to array of 13 data bytes.
+ *  @return Checksum.
+ */
+static guchar calc_chksum_14(guchar* dta)
+{
+	guchar cnt, chs;
+
+	for (chs = 0, cnt = 0; cnt < 13; cnt++)
+		chs += dta[cnt];
+
+	return (64 - chs) & MASK_6BITS;
+}
+
+/** Check 14-byte message, Metrahit 2x. */
+static int chk_msg14(struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	int retc;
+	gboolean isreq; /* Message is request to multimeter (otherwise response) */
+	uint8_t addr;  /* Adaptor address */
+
+	retc = SR_OK;
+
+	/* Check parameters and message */
+	if (!sdi || !(devc = sdi->priv))
+		return SR_ERR_ARG;
+
+	if (devc->buflen != 14) {
+		sr_err("process_msg_14(): Msg len 14 expected!");
+		return SR_ERR_ARG;
+	}
+
+	isreq = devc->buf[1] == 0x2b;
+	if (isreq)
+		addr = devc->buf[0] >> 2;
+	else
+		addr = devc->buf[0] & 0x0f;
+
+	if ((devc->addr != addr) && !(isreq && (addr == 0))) {
+		sr_err("process_msg_14(): Address mismatch, msg for other device!");
+		retc = SR_ERR_ARG;
+	}
+
+	if (devc->buf[1] == 0) { /* Error msg from device! */
+		retc = SR_ERR_ARG;
+		switch (devc->buf[2]) {
+		case 1: /* Not used */
+			sr_err("Device: Illegal error code!");
+			break;
+		case 2: /* Incorrect check sum of received block */
+			sr_err("Device: Incorrect checksum in cmd!");
+			break;
+		case 3: /* Incorrect length of received block */
+			sr_err("Device: Incorrect block length in cmd!");
+			break;
+		case 4: /* Incorrect 2nd or 3rd byte */
+			sr_err("Device: Incorrect byte 2 or 3 in cmd!");
+			break;
+		case 5: /* Parameter out of range */
+			sr_err("Device: Parameter out of range!");
+			break;
+		default:
+			sr_err("Device: Unknown error code!");
+		}
+		retc = SR_ERR_ARG;
+	}
+	else if (!isreq && ((devc->buf[1] != 0x27) || (devc->buf[2] != 0x3f))) {
+		sr_err("process_msg_14(): byte 1/2 unexpected!");
+		retc = SR_ERR_ARG;
+	}
+
+	if (calc_chksum_14(devc->buf) != devc->buf[13]) {
+		sr_err("process_msg_14(): Invalid checksum!");
+		retc = SR_ERR_ARG;
+	}
+
+	if (retc != SR_OK)
+		dump_msg14(devc->buf, TRUE);
+
+	return retc;
+}
+
+/** Check 14-byte message, Metrahit 2x. */
+SR_PRIV int process_msg14(struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	int retc;
+	uint8_t addr;
+	uint8_t cnt, dgt;
+
+	if ((retc = chk_msg14(sdi)) != SR_OK)
+		return retc;
+
+	devc = sdi->priv;
+
+	clean_ctmv_rs_v(devc);
+	addr = devc->buf[0] & MASK_6BITS;
+	if (addr != devc->addr)
+		sr_info("Device address mismatch %d/%d!", addr, devc->addr);
+
+	switch (devc->buf[3]) { /* That's the command this reply is for */
+	/* 0 cannot occur, the respective message is not a 14-byte message */
+	case 1: /* Read first free and occupied address */
+		sr_spew("Cmd %d unimplemented!", devc->buf[3]);
+		break;
+	case 2: /* Clear all RAM in multimeter */
+		sr_spew("Cmd %d unimplemented!", devc->buf[3]);
+		break;
+	case 3: /* Read firmware version and status */
+		sr_spew("Cmd 3, Read firmware and status", devc->buf[3]);
+		switch (devc->cmd_idx) {
+		case 0:
+			devc->fw_ver_maj = devc->buf[5];
+			devc->fw_ver_min = devc->buf[4];
+			sr_spew("Firmware version %d.%d", (int)devc->fw_ver_maj, (int)devc->fw_ver_min);
+			sr_spew("Rotary Switch Position (1..10): %d", (int)devc->buf[6]);
+			/** Docs say values 0..9, but that's not true */
+			sr_spew("Measurement Function: %d ", (int)devc->buf[7]);
+			decode_ctmv_2x(devc->buf[7], devc);
+			sr_spew("Range: 0x%x", devc->buf[8]);
+			decode_rs_2x_TR2(devc->buf[8] & 0x0f, devc);  /* Docs wrong, uses conversion table TR_2! */
+			devc->autorng = (devc->buf[8] & 0x20) == 0;
+			// TODO 9, 10: 29S special functions
+			devc->ubatt = 0.1 * (float)devc->buf[11];
+			devc->model = gmc_decode_model_bd(devc->buf[12]);
+			sr_spew("Model=%s, battery voltage=%2.1f V", gmc_model_str(devc->model), (double)devc->ubatt);
+			break;
+		case 1:
+			sr_spew("Internal version %d.%d", (int)devc->buf[5], (int)devc->buf[4]);
+			sr_spew("Comm mode: 0x%x", (int)devc->buf[6]);
+			sr_spew("Block cnt%%64: %d", (int)devc->buf[7]);
+			sr_spew("drpCi: %d  drpCh: %d", (int)devc->buf[8], (int)devc->buf[9]);
+			// Semantics undocumented. Possibly Metrahit 29S dropouts stuff?
+			break;
+		default:
+			sr_spew("Cmd 3: Unknown cmd_idx=%d", devc->cmd_idx);
+			break;
+		}
+		break;
+	case 4: /* Set real time, date, sample rate, trigger, ... */
+		sr_spew("Cmd %d unimplemented!", devc->buf[3]);
+		break;
+	case 5: /* Read real time, date, sample rate, trigger... */
+		sr_spew("Cmd %d unimplemented!", devc->buf[3]);
+		break;
+	case 6: /* Set modes or power off */
+		sr_spew("Cmd %d unimplemented!", devc->buf[3]);
+		break;
+	case 7: /* Set measurement function, range, autom/man. */
+		sr_spew("Cmd %d unimplemented!", devc->buf[3]);
+		break;
+	case 8: /* Get one measurement value */
+		sr_spew("Cmd 8, get one measurement value");
+		sr_spew("Measurement Function: %d ", (int)devc->buf[5]);
+		decode_ctmv_2x(devc->buf[5], devc);
+		if (!(devc->buf[6] & 0x10)) /* If bit4=0, old data. */
+			return SR_OK;
+
+		decode_rs_2x_TR2(devc->buf[6] & 0x0f, devc); // The docs say conversion table TR_3, but that does not work
+		setmqf(devc, SR_MQFLAG_AUTORANGE, devc->autorng);
+		/* 6 digits */
+		for (cnt = 0; cnt < 6; cnt++) {
+			dgt = bc(devc->buf[7 + cnt]);
+			if (dgt == 10) { /* Overload */
+				devc->value = NAN;
+				devc->scale = 1.0;
+				break;
+			}
+			else if (dgt == 13) { /* FUSE */
+				sr_err("FUSE!");
+			}
+			else if (dgt == 14) { /* Function recognition mode, OPEN */
+				sr_info("Function recognition mode, OPEN!");
+				devc->value = NAN;
+				devc->scale = 1.0;
+				break;
+			}
+			devc->value += pow(10.0, cnt) * dgt;
+		}
+		sr_spew("process_msg14() value=%f scale=%f scale1000=%d mq=%d "
+			"unit=%d mqflags=0x%02llx", devc->value, devc->scale,
+			devc->scale1000, devc->mq, devc->unit, devc->mqflags);
+		if (devc->value != NAN)
+			devc->value *= devc->scale * pow(1000.0, devc->scale1000);
+
+		send_value(sdi);
+
+		break;
+	default:
+		sr_spew("Unknown cmd %d!", devc->buf[3]);
+		break;
+	}
+
+	return SR_OK;
+}
+
+/** Data reception callback function. */
 SR_PRIV int gmc_mh_1x_2x_receive_data(int fd, int revents, void *cb_data)
 {
-	const struct sr_dev_inst *sdi;
+	struct sr_dev_inst *sdi;
+	struct dev_context *devc;
+	struct sr_serial_dev_inst *serial;
+	uint8_t buf, msgt;
+	int len;
+	gdouble elapsed_s;
+
+	(void)fd;
+
+	if (!(sdi = cb_data))
+		return TRUE;
+
+	if (!(devc = sdi->priv))
+		return TRUE;
+
+	serial = sdi->conn;
+
+	if (revents == G_IO_IN) { /* Serial data arrived. */
+		while (GMC_BUFSIZE - devc->buflen - 1 > 0) {
+			len = serial_read(serial, devc->buf + devc->buflen, 1);
+			if (len < 1)
+				break;
+			buf = *(devc->buf + devc->buflen);
+			sr_spew("read 0x%02x/%d/%d", buf, buf, buf & MSGC_MASK);
+			devc->buflen += len;
+			if (!devc->settings_ok) {
+				/*
+				 * If no device type/settings record processed
+				 * yet, wait for one.
+				 */
+				if ((devc->buf[0] & MSGID_MASK) != MSGID_INF) {
+					devc->buflen = 0;
+					continue;
+				}
+				devc->settings_ok = TRUE;
+			}
+
+			msgt = devc->buf[0] & MSGID_MASK;
+			switch (msgt) {
+			case MSGID_INF:
+				if (devc->buflen == 13) {
+					process_msg_inf_13(sdi);
+					devc->buflen = 0;
+					continue;
+				} else if ((devc->buflen == 10) &&
+					   (devc->model <= METRAHIT_18S)) {
+					process_msg_inf_10(sdi);
+					devc->buflen = 0;
+					continue;
+				}
+				else if ((devc->buflen >= 5) &&
+					 (devc->buf[devc->buflen - 1] &
+					  MSGID_MASK) != MSGID_DATA) {
+					/*
+					 * Char just received is beginning
+					 * of next message.
+					 */
+					process_msg_inf_5(sdi);
+					devc->buf[0] =
+							devc->buf[devc->buflen - 1];
+					devc->buflen = 1;
+					continue;
+				}
+				break;
+			case MSGID_DTA:
+			case MSGID_D10:
+				if (devc->buflen == 6) {
+					process_msg_dta_6(sdi);
+					devc->buflen = 0;
+				}
+				break;
+			case MSGID_DATA:
+				sr_err("Comm error, unexpected data byte!");
+				devc->buflen = 0;
+				break;
+			}
+		}
+	}
+
+	/* If number of samples or time limit reached, stop aquisition. */
+	if (devc->limit_samples && (devc->num_samples >= devc->limit_samples))
+		sdi->driver->dev_acquisition_stop(sdi, cb_data);
+
+	if (devc->limit_msec) {
+		elapsed_s = g_timer_elapsed(devc->elapsed_msec, NULL);
+		if ((elapsed_s * 1000) >= devc->limit_msec)
+			sdi->driver->dev_acquisition_stop(sdi, cb_data);
+	}
+
+	return TRUE;
+}
+
+SR_PRIV int gmc_mh_2x_receive_data(int fd, int revents, void *cb_data)
+{
+	struct sr_dev_inst *sdi;
 	struct dev_context *devc;
+	struct sr_serial_dev_inst *serial;
+	uint8_t buf;
+	int len;
+	gdouble elapsed_s;
 
 	(void)fd;
 
@@ -32,9 +1181,356 @@ SR_PRIV int gmc_mh_1x_2x_receive_data(int fd, int revents, void *cb_data)
 	if (!(devc = sdi->priv))
 		return TRUE;
 
-	if (revents == G_IO_IN) {
-		/* TODO */
+	serial = sdi->conn;
+
+	if (revents == G_IO_IN) { /* Serial data arrived. */
+		while (GMC_BUFSIZE - devc->buflen - 1 > 0) {
+			len = serial_read(serial, devc->buf + devc->buflen, 1);
+			if (len < 1)
+				break;
+			buf = *(devc->buf + devc->buflen);
+			sr_spew("read 0x%02x/%d/%d", buf, buf, buf & MASK_6BITS);
+			devc->buf[devc->buflen] &= MASK_6BITS;
+			devc->buflen += len;
+
+			if (devc->buflen == 14) {
+				devc->response_pending = FALSE;
+				sr_spew("gmc_mh_2x_receive_data processing msg");
+				process_msg14(sdi);
+				devc->buflen = 0;
+			}
+		}
+	}
+
+	/* If number of samples or time limit reached, stop aquisition. */
+	if (devc->limit_samples && (devc->num_samples >= devc->limit_samples))
+		sdi->driver->dev_acquisition_stop(sdi, cb_data);
+
+	if (devc->limit_msec) {
+		elapsed_s = g_timer_elapsed(devc->elapsed_msec, NULL);
+		if ((elapsed_s * 1000) >= devc->limit_msec)
+			sdi->driver->dev_acquisition_stop(sdi, cb_data);
+	}
+
+	/* Request next data set, if required */
+	if (sdi->status == SR_ST_ACTIVE) {
+		if (devc->response_pending) {
+			gint64 elapsed_us = g_get_monotonic_time() - devc->req_sent_at;
+			if (elapsed_us > 1*1000*1000) /* Timeout! */
+				devc->response_pending = FALSE;
+		}
+		if (!devc->response_pending) {
+			devc->cmd_seq++;
+			if (devc->cmd_seq % 10 == 0) {
+				if (req_stat14(sdi, FALSE) != SR_OK)
+					return FALSE;
+			}
+			else if (req_meas14(sdi) != SR_OK)
+				return FALSE;
+		}
 	}
 
 	return TRUE;
 }
+
+/** Create 14 (42) byte command for Metrahit 2x multimeter in bidir mode.
+ *
+ *  Actually creates 42 bytes due to the encoding method used.
+ *  @param[in] addr Device address (0=adapter, 1..15 multimeter; for byte 0).
+ *  @param[in] func Function code (byte 3).
+ *  @param[in] params Further parameters (9 bytes)
+ *  @param[out] buf Buffer to create msg in (42 bytes).
+ */
+void create_cmd_14(guchar addr, guchar func, guchar* params, guchar* buf)
+{
+	uint8_t dta[14];	/* Unencoded message */
+	int cnt;
+
+	if (!params || !buf)
+		return;
+
+	/* 0: Address */
+	dta[0] = ((addr << 2) | 0x03) & MASK_6BITS;
+
+	/* 1-3: Set command header */
+	dta[1] = 0x2b;
+	dta[2] = 0x3f;
+	dta[3] = func;
+
+	/* 4-12: Copy further parameters */
+	for (cnt = 0; cnt < 9; cnt++)
+		dta[cnt+4] = (params[cnt] & MASK_6BITS);
+
+	/* 13: Checksum (b complement) */
+	dta[13] = calc_chksum_14(dta);
+
+	/* The whole message is packed into 3 bytes per byte now (lower 6 bits only) the most
+	 * peculiar way I have ever seen. Possibly to improve IR communication? */
+	for (cnt = 0; cnt < 14; cnt++) {
+		buf[3*cnt] = (dta[cnt] & 0x01 ? 0x0f : 0) | (dta[cnt] & 0x02 ? 0xf0 : 0);
+		buf[3*cnt + 1] = (dta[cnt] & 0x04 ? 0x0f : 0) | (dta[cnt] & 0x08 ? 0xf0 : 0);
+		buf[3*cnt + 2] = (dta[cnt] & 0x10 ? 0x0f : 0) | (dta[cnt] & 0x20 ? 0xf0 : 0);
+	}
+}
+
+/** Request one measurement from 2x multimeter (msg 8).
+ *
+ */
+int req_meas14(const struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	struct sr_serial_dev_inst *serial;
+	uint8_t params[9];
+	uint8_t msg[42];
+
+	if (!sdi || !(devc = sdi->priv) || !(serial = sdi->conn))
+		return SR_ERR;
+
+	memset(params, 0, sizeof(params));
+	params[0] = 0;
+	devc->cmd_idx = 0;
+	create_cmd_14(devc->addr, 8, params, msg);
+	devc->req_sent_at = g_get_monotonic_time();
+	if (serial_write(serial, msg, sizeof(msg)) == -1) {
+		return SR_ERR;
+	}
+
+	devc->response_pending = TRUE;
+
+	return SR_OK;
+}
+
+/** Request status from 2x multimeter (msg 3).
+ *  @param[in] power_on Try to power on powered off multimeter by sending additional messages.
+ */
+int req_stat14(const struct sr_dev_inst *sdi, gboolean power_on)
+{
+	struct dev_context *devc;
+	struct sr_serial_dev_inst *serial;
+	uint8_t params[9];
+	uint8_t msg[42];
+
+	if (!sdi || !(devc = sdi->priv) || !(serial = sdi->conn))
+		return SR_ERR;
+
+	memset(params, 0, sizeof(params));
+	params[0] = 0;
+	devc->cmd_idx = 0;
+	create_cmd_14(devc->addr, 3, params, msg);
+
+	if (power_on) {
+		sr_info("Write some data and wait 3s to turn on powered off device...");
+		if (serial_write(serial, msg, sizeof(msg)) < 0)
+			return SR_ERR;
+		g_usleep(1*1000*1000);
+		if (serial_write(serial, msg, sizeof(msg)) < 0)
+			return SR_ERR;
+		g_usleep(1*1000*1000);
+		if (serial_write(serial, msg, sizeof(msg)) < 0)
+			return SR_ERR;
+		g_usleep(1*1000*1000);
+		serial_flush(serial);
+	}
+
+	/* Write message and wait for reply */
+	devc->req_sent_at = g_get_monotonic_time();
+	if (serial_write(serial, msg, sizeof(msg)) == -1) {
+		return SR_ERR;
+	}
+
+	devc->response_pending = TRUE;
+
+	return SR_OK;
+}
+
+/** Decode model in "send mode".
+ *
+ * @param[in] mcode Model code.
+ * @return Model code.
+ */
+SR_PRIV int gmc_decode_model_sm(uint8_t mcode)
+{
+	if (mcode > 0xf) {
+		sr_err("decode_model(%d): Model code 0..15 expected!", mcode);
+		return METRAHIT_NONE;
+	}
+
+	switch(mcode) {
+	case 0x04: /* 0100b */
+		return METRAHIT_12S;
+	case 0x08: /* 1000b */
+		return METRAHIT_13S14A;
+	case 0x09: /* 1001b */
+		return METRAHIT_14S;
+	case 0x0A: /* 1010b */
+		return METRAHIT_15S;
+	case 0x0B: /* 1011b */
+		return METRAHIT_16S;
+	case 0x06: /* 0110b (undocumented by GMC!) */
+		return METRAHIT_16I;
+	case 0x0D: /* 1101b */
+		return METRAHIT_18S;
+	case 0x02: /* 0010b */
+		return METRAHIT_22SM;
+	case 0x03: /* 0011b */
+		return METRAHIT_23S;
+	case 0x0f: /* 1111b */
+		return METRAHIT_24S;
+	case 0x05: /* 0101b */
+		return METRAHIT_25S;
+	case 0x01: /* 0001b */
+		return METRAHIT_26SM;
+	case 0x0c: /* 1100b */
+		return METRAHIT_28S;
+	case 0x0e: /* 1110b */
+		return METRAHIT_29S;
+	default:
+		sr_err("Unknown model code %d!", mcode);
+		return METRAHIT_NONE;
+	}
+}
+
+/** Convert GMC model code in bidirectional mode to sigrok-internal one.
+ *
+ *  @param[in] mcode Model code.
+ *
+ *  @return Model code.
+ */
+SR_PRIV int gmc_decode_model_bd(uint8_t mcode)
+{
+	switch (mcode & 0x1f) {
+	case 2:
+		if (mcode & 0x20)
+			return METRAHIT_22M;
+		else
+			return METRAHIT_22S;
+	case 3:
+		return METRAHIT_23S;
+	case 4:
+		return METRAHIT_24S;
+	case 5:
+		return METRAHIT_25S;
+	case 1:
+		if (mcode & 0x20)
+			return METRAHIT_26M;
+		else
+			return METRAHIT_26S;
+	case 12:
+		return METRAHIT_28S;
+	case 14:
+		return METRAHIT_29S;
+	default:
+		sr_err("Unknown model code %d!", mcode);
+		return METRAHIT_NONE;
+	}
+}
+
+/** Convert sigrok-internal model code to string.
+ *
+ *  @param[in] mcode Model code.
+ *
+ *  @return Model code string.
+ */
+SR_PRIV const char *gmc_model_str(enum model mcode)
+{
+	switch (mcode) {
+	case METRAHIT_NONE:
+		return "-uninitialized model variable-";
+	case METRAHIT_12S:
+		return "METRAHit 12S";
+	case METRAHIT_13S14A:
+		return "METRAHit 13S/14A";
+	case METRAHIT_14S:
+		return "METRAHit 14S";
+	case METRAHIT_15S:
+		return "METRAHit 15S";
+	case METRAHIT_16S:
+		return "METRAHit 16S";
+	case METRAHIT_16I:
+		return "METRAHit 16I";
+	case METRAHIT_18S:
+		return "METRAHit 18S";
+	case METRAHIT_22SM:
+		return "METRAHit 22S/M";
+	case METRAHIT_22S:
+		return "METRAHit 22S";
+	case METRAHIT_22M:
+		return "METRAHit 22M";
+	case METRAHIT_23S:
+		return "METRAHit 23S";
+	case METRAHIT_24S:
+		return "METRAHit 24S";
+	case METRAHIT_25S:
+		return "METRAHit 25S";
+	case METRAHIT_26SM:
+		return "METRAHit 26S/M";
+	case METRAHIT_26S:
+		return "METRAHit 26S";
+	case METRAHIT_26M:
+		return "METRAHit 26M";
+	case METRAHIT_28S:
+		return "METRAHit 28S";
+	case METRAHIT_29S:
+		return "METRAHit 29S";
+	default:
+		return "Unknown model code";
+	}
+}
+
+
+/** @copydoc sr_dev_driver.config_set
+ */
+SR_PRIV int config_set(int key, GVariant *data, const struct sr_dev_inst *sdi,
+		       const struct sr_probe_group *probe_group)
+{
+	struct dev_context *devc;
+	uint8_t params[9];
+	uint8_t msg[42];
+
+	(void)probe_group;
+
+	if (sdi->status != SR_ST_ACTIVE)
+		return SR_ERR_DEV_CLOSED;
+
+	if (!(devc = sdi->priv)) {
+		sr_err("sdi->priv was NULL.");
+		return SR_ERR_BUG;
+	}
+
+	switch (key) {
+	case SR_CONF_POWER_OFF:
+		if (devc->model < METRAHIT_2X)
+			return SR_ERR_NA;
+		if (!g_variant_get_boolean(data))
+			return SR_ERR;
+		sr_info("Powering device off.");
+
+		memset(params, 0, sizeof(params));
+		params[0] = 5;
+		params[1] = 5;
+		create_cmd_14(devc->addr, 6, params, msg);
+		if (serial_write(sdi->conn, msg, sizeof(msg)) == -1)
+			return SR_ERR;
+		else
+			g_usleep(2000000); /* Wait to ensure transfer before interface switched off. */
+		break;
+	case SR_CONF_LIMIT_MSEC:
+		if (g_variant_get_uint64(data) == 0) {
+			sr_err("LIMIT_MSEC can't be 0.");
+			return SR_ERR;
+		}
+		devc->limit_msec = g_variant_get_uint64(data);
+		sr_dbg("Setting time limit to %" PRIu64 "ms.",
+		       devc->limit_msec);
+		break;
+	case SR_CONF_LIMIT_SAMPLES:
+		devc->limit_samples = g_variant_get_uint64(data);
+		sr_dbg("Setting sample limit to %" PRIu64 ".",
+		       devc->limit_samples);
+		break;
+	default:
+		return SR_ERR_NA;
+	}
+
+	return SR_OK;
+}