X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=blobdiff_plain;f=src%2Fhardware%2Fhp-3478a%2Fprotocol.c;h=2e9130b022a9ab01832701ebdae41eb0c1533c47;hp=3ddce5884aa1bddd72a199f4823bae3e2cde5f2c;hb=569165c0e44323ce8a4baf1da4d540e8976e9d33;hpb=94cf02d0c24580322fdf9238a96a563205b943d2

diff --git a/src/hardware/hp-3478a/protocol.c b/src/hardware/hp-3478a/protocol.c
index 3ddce588..2e9130b0 100644
--- a/src/hardware/hp-3478a/protocol.c
+++ b/src/hardware/hp-3478a/protocol.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the libsigrok project.
  *
- * Copyright (C) 2017-2018 Frank Stettner <frank-stettner@gmx.net>
+ * Copyright (C) 2017-2021 Frank Stettner <frank-stettner@gmx.net>
  *
  * 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
@@ -69,9 +69,8 @@ SR_PRIV int hp_3478a_set_mq(const struct sr_dev_inst *sdi, enum sr_mq mq,
 	struct sr_scpi_dev_inst *scpi = sdi->conn;
 	struct dev_context *devc = sdi->priv;
 
-	/* No need to send command if we're not changing measurement type. */
-	if (devc->measurement_mq == mq &&
-		((devc->measurement_mq_flags & mq_flags) == mq_flags))
+	/* No need to send a command if we're not changing the measurement type. */
+	if (devc->measurement_mq == mq && devc->measurement_mq_flag == mq_flags)
 		return SR_OK;
 
 	for (i = 0; i < ARRAY_SIZE(sr_mq_to_cmd_map); i++) {
@@ -89,19 +88,63 @@ SR_PRIV int hp_3478a_set_mq(const struct sr_dev_inst *sdi, enum sr_mq mq,
 	return SR_ERR_NA;
 }
 
+SR_PRIV int hp_3478a_set_range(const struct sr_dev_inst *sdi, int range_exp)
+{
+	int ret;
+	struct sr_scpi_dev_inst *scpi = sdi->conn;
+	struct dev_context *devc = sdi->priv;
+
+	/* No need to send command if we're not changing the range. */
+	if (devc->range_exp == range_exp)
+		return SR_OK;
+
+	/* -99 is a dummy exponent for auto ranging. */
+	if (range_exp == -99)
+		ret = sr_scpi_send(scpi, "RA");
+	else
+		ret = sr_scpi_send(scpi, "R%i", range_exp);
+	if (ret != SR_OK)
+		return ret;
+
+	return hp_3478a_get_status_bytes(sdi);
+}
+
+SR_PRIV int hp_3478a_set_digits(const struct sr_dev_inst *sdi, uint8_t digits)
+{
+	int ret;
+	struct sr_scpi_dev_inst *scpi = sdi->conn;
+	struct dev_context *devc = sdi->priv;
+
+	/* No need to send command if we're not changing the range. */
+	if (devc->spec_digits == digits)
+		return SR_OK;
+
+	/* digits are based on devc->spec_digits, so we have to substract 1 */
+	ret = sr_scpi_send(scpi, "N%i", digits-1);
+	if (ret != SR_OK)
+		return ret;
+
+	return hp_3478a_get_status_bytes(sdi);
+}
+
 static int parse_range_vdc(struct dev_context *devc, uint8_t range_byte)
 {
-	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30MV)
+	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30MV) {
+		devc->range_exp = -2;
 		devc->enc_digits = devc->spec_digits - 2;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300MV)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300MV) {
+		devc->range_exp = -1;
 		devc->enc_digits = devc->spec_digits - 3;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_3V)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_3V) {
+		devc->range_exp = 0;
 		devc->enc_digits = devc->spec_digits - 1;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30V)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30V) {
+		devc->range_exp = 1;
 		devc->enc_digits = devc->spec_digits - 2;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300V)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300V) {
+		devc->range_exp = 2;
 		devc->enc_digits = devc->spec_digits - 3;
-	else
+	} else
 		return SR_ERR_DATA;
 
 	return SR_OK;
@@ -109,15 +152,19 @@ static int parse_range_vdc(struct dev_context *devc, uint8_t range_byte)
 
 static int parse_range_vac(struct dev_context *devc, uint8_t range_byte)
 {
-	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300MV)
+	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300MV) {
+		devc->range_exp = -1;
 		devc->enc_digits = devc->spec_digits - 3;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_3V)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_3V) {
+		devc->range_exp = 0;
 		devc->enc_digits = devc->spec_digits - 1;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_30V)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_30V) {
+		devc->range_exp = 1;
 		devc->enc_digits = devc->spec_digits - 2;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300V)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300V) {
+		devc->range_exp = 2;
 		devc->enc_digits = devc->spec_digits - 3;
-	else
+	} else
 		return SR_ERR_DATA;
 
 	return SR_OK;
@@ -125,11 +172,13 @@ static int parse_range_vac(struct dev_context *devc, uint8_t range_byte)
 
 static int parse_range_a(struct dev_context *devc, uint8_t range_byte)
 {
-	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_300MA)
+	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_300MA) {
+		devc->range_exp = -1;
 		devc->enc_digits = devc->spec_digits - 3;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_3A)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_3A) {
+		devc->range_exp = 0;
 		devc->enc_digits = devc->spec_digits - 1;
-	else
+	} else
 		return SR_ERR_DATA;
 
 	return SR_OK;
@@ -137,21 +186,28 @@ static int parse_range_a(struct dev_context *devc, uint8_t range_byte)
 
 static int parse_range_ohm(struct dev_context *devc, uint8_t range_byte)
 {
-	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30R)
+	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30R) {
+		devc->range_exp = 1;
 		devc->enc_digits = devc->spec_digits - 2;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300R)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300R) {
+		devc->range_exp = 2;
 		devc->enc_digits = devc->spec_digits - 3;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3KR)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3KR) {
+		devc->range_exp = 3;
 		devc->enc_digits = devc->spec_digits - 1;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30KR)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30KR) {
+		devc->range_exp = 4;
 		devc->enc_digits = devc->spec_digits - 2;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300KR)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300KR) {
+		devc->range_exp = 5;
 		devc->enc_digits = devc->spec_digits - 3;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3MR)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3MR) {
+		devc->range_exp = 6;
 		devc->enc_digits = devc->spec_digits - 1;
-	else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30MR)
+	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30MR) {
+		devc->range_exp = 7;
 		devc->enc_digits = devc->spec_digits - 2;
-	else
+	} else
 		return SR_ERR_DATA;
 
 	return SR_OK;
@@ -170,15 +226,18 @@ static int parse_function_byte(struct dev_context *devc, uint8_t function_byte)
 		return SR_ERR_DATA;
 
 	/* Function + Range */
-	devc->measurement_mq_flags = 0;
+	devc->measurement_mq_flag = 0;
+	devc->acquisition_mq_flags = 0;
 	if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_VDC) {
 		devc->measurement_mq = SR_MQ_VOLTAGE;
-		devc->measurement_mq_flags |= SR_MQFLAG_DC;
+		devc->measurement_mq_flag = SR_MQFLAG_DC;
+		devc->acquisition_mq_flags |= SR_MQFLAG_DC;
 		devc->measurement_unit = SR_UNIT_VOLT;
 		parse_range_vdc(devc, function_byte);
 	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_VAC) {
 		devc->measurement_mq = SR_MQ_VOLTAGE;
-		devc->measurement_mq_flags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
+		devc->measurement_mq_flag = SR_MQFLAG_AC;
+		devc->acquisition_mq_flags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 		devc->measurement_unit = SR_UNIT_VOLT;
 		parse_range_vac(devc, function_byte);
 	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_2WR) {
@@ -187,17 +246,20 @@ static int parse_function_byte(struct dev_context *devc, uint8_t function_byte)
 		parse_range_ohm(devc, function_byte);
 	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_4WR) {
 		devc->measurement_mq = SR_MQ_RESISTANCE;
-		devc->measurement_mq_flags |= SR_MQFLAG_FOUR_WIRE;
+		devc->measurement_mq_flag = SR_MQFLAG_FOUR_WIRE;
+		devc->acquisition_mq_flags |= SR_MQFLAG_FOUR_WIRE;
 		devc->measurement_unit = SR_UNIT_OHM;
 		parse_range_ohm(devc, function_byte);
 	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_ADC) {
 		devc->measurement_mq = SR_MQ_CURRENT;
-		devc->measurement_mq_flags |= SR_MQFLAG_DC;
+		devc->measurement_mq_flag = SR_MQFLAG_DC;
+		devc->acquisition_mq_flags |= SR_MQFLAG_DC;
 		devc->measurement_unit = SR_UNIT_AMPERE;
 		parse_range_a(devc, function_byte);
 	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_AAC) {
 		devc->measurement_mq = SR_MQ_CURRENT;
-		devc->measurement_mq_flags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
+		devc->measurement_mq_flag = SR_MQFLAG_AC;
+		devc->acquisition_mq_flags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 		devc->measurement_unit = SR_UNIT_AMPERE;
 		parse_range_a(devc, function_byte);
 	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_EXR) {
@@ -242,10 +304,11 @@ static int parse_status_byte(struct dev_context *devc, uint8_t status_byte)
 		devc->auto_zero = FALSE;
 
 	/* Auto-Range */
-	if ((status_byte & STATUS_AUTO_RANGE) == STATUS_AUTO_RANGE)
-		devc->measurement_mq_flags |= SR_MQFLAG_AUTORANGE;
-	else
-		devc->measurement_mq_flags &= ~SR_MQFLAG_AUTORANGE;
+	if ((status_byte & STATUS_AUTO_RANGE) == STATUS_AUTO_RANGE) {
+		devc->acquisition_mq_flags |= SR_MQFLAG_AUTORANGE;
+		devc->range_exp = -99;
+	} else
+		devc->acquisition_mq_flags &= ~SR_MQFLAG_AUTORANGE;
 
 	/* Internal trigger */
 	if ((status_byte & STATUS_INT_TRIGGER) == STATUS_INT_TRIGGER)
@@ -392,7 +455,7 @@ static void acq_send_measurement(struct sr_dev_inst *sdi)
 	encoding.digits = devc->enc_digits;
 
 	meaning.mq = devc->measurement_mq;
-	meaning.mqflags = devc->measurement_mq_flags;
+	meaning.mqflags = devc->acquisition_mq_flags;
 	meaning.unit = devc->measurement_unit;
 	meaning.channels = sdi->channels;
 
@@ -406,6 +469,7 @@ SR_PRIV int hp_3478a_receive_data(int fd, int revents, void *cb_data)
 	struct sr_scpi_dev_inst *scpi;
 	struct sr_dev_inst *sdi;
 	struct dev_context *devc;
+	char status_register;
 
 	(void)fd;
 	(void)revents;
@@ -416,18 +480,32 @@ SR_PRIV int hp_3478a_receive_data(int fd, int revents, void *cb_data)
 	scpi = sdi->conn;
 
 	/*
-	 * This is necessary to get the actual range for the encoding digits.
-	 * When SPoll is implemmented, this can be done via SPoll.
+	 * TODO: Wait for SRQ from the DMM when a new measurement is available.
+	 *       For now, we don't wait for a SRQ, but just do a SPoll and
+	 *       check the Data Ready bit (0x01).
+	 *       This is necessary, because (1) reading a value will block the
+	 *       bus until a measurement is available and (2) when switching
+	 *       ranges, there could be a timeout.
 	 */
-	if (hp_3478a_get_status_bytes(sdi) != SR_OK)
+	if (sr_scpi_gpib_spoll(scpi, &status_register) != SR_OK)
+		return FALSE;
+	if (!(((uint8_t)status_register) & 0x01))
+		return TRUE;
+
+	/* Get a reading from the DMM. */
+	if (sr_scpi_get_double(scpi, NULL, &devc->measurement) != SR_OK)
 		return FALSE;
 
+	/* Check for overflow. */
+	if (devc->measurement >= 9.998e+9)
+		devc->measurement = INFINITY;
+
 	/*
-	 * TODO: Implement GPIB-SPoll, to get notified by a SRQ when a new
-	 *       measurement is available. This is necessary, because when
-	 *       switching ranges, there could be a timeout.
+	 * This is necessary to get the actual range for the encoding digits.
+	 * Must be called after reading the value, because it resets the
+	 * status register!
 	 */
-	if (sr_scpi_get_double(scpi, NULL, &devc->measurement) != SR_OK)
+	if (hp_3478a_get_status_bytes(sdi) != SR_OK)
 		return FALSE;
 
 	acq_send_measurement(sdi);