scpi-dmm: model and MQ dependent delay when switching functions

Some models are slow to switch meter functions to specific MQs. This was
observed with 34405A and AC V/I modes, where USB connections timed out
and suffered from pipe errors.

Add an optional delay after "CONF:<mode> [<range>]" SCPI requests. The
duration of the delay is per model, the use of the delay is per MQ on
that model. The 200ms delay for 34405A was found by experimentation.

Speaking about 34405A: Only the "INIT" request in temperature mode
remains as an issue, which is not covered by this commit's approach.

diff --git a/src/hardware/scpi-dmm/api.c b/src/hardware/scpi-dmm/api.c
index a462fdcf5ef6830fac9af99ce9c3cbb3189445c4..95d8a08287f480ee4f5f097b2ff0559cc4332e69 100644 (file)
--- a/src/hardware/scpi-dmm/api.c
+++ b/src/hardware/scpi-dmm/api.c
@@ -127,9 +127,9 @@ static const struct scpi_command cmdset_owon[] = {
 
 static const struct mqopt_item mqopts_agilent_34405a[] = {
        { SR_MQ_VOLTAGE, SR_MQFLAG_DC, "VOLT:DC", "VOLT ", NO_DFLT_PREC, FLAGS_NONE, },
-       { SR_MQ_VOLTAGE, SR_MQFLAG_AC, "VOLT:AC", "VOLT:AC ", NO_DFLT_PREC, FLAGS_NONE, },
+       { SR_MQ_VOLTAGE, SR_MQFLAG_AC, "VOLT:AC", "VOLT:AC ", NO_DFLT_PREC, FLAG_CONF_DELAY, },
        { SR_MQ_CURRENT, SR_MQFLAG_DC, "CURR:DC", "CURR ", NO_DFLT_PREC, FLAGS_NONE, },
-       { SR_MQ_CURRENT, SR_MQFLAG_AC, "CURR:AC", "CURR:AC ", NO_DFLT_PREC, FLAGS_NONE, },
+       { SR_MQ_CURRENT, SR_MQFLAG_AC, "CURR:AC", "CURR:AC ", NO_DFLT_PREC, FLAG_CONF_DELAY, },
        { SR_MQ_RESISTANCE, 0, "RES", "RES ", NO_DFLT_PREC, FLAGS_NONE, },
        { SR_MQ_RESISTANCE, SR_MQFLAG_FOUR_WIRE, "FRES", "FRES ", NO_DFLT_PREC, FLAGS_NONE, },
        { SR_MQ_CONTINUITY, 0, "CONT", "CONT", -1, FLAG_NO_RANGE, },
@@ -204,7 +204,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 5, cmdset_agilent, ARRAY_AND_SIZE(mqopts_agilent_34405a),
                scpi_dmm_get_meas_agilent,
                ARRAY_AND_SIZE(devopts_generic_range),
-               0, 0, FALSE,
+               0, 200 * 1000, 0, FALSE,
                scpi_dmm_get_range_text, scpi_dmm_set_range_from_text, NULL,
        },
        {
@@ -212,7 +212,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 6, cmdset_hp, ARRAY_AND_SIZE(mqopts_agilent_34405a),
                scpi_dmm_get_meas_agilent,
                ARRAY_AND_SIZE(devopts_generic),
-               0, 0, FALSE,
+               0, 0, 0, FALSE,
                NULL, NULL, NULL,
        },
        {
@@ -220,7 +220,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 6, cmdset_gwinstek, ARRAY_AND_SIZE(mqopts_gwinstek_gdm8200a),
                scpi_dmm_get_meas_gwinstek,
                ARRAY_AND_SIZE(devopts_generic),
-               2500 * 1000, 0, FALSE,
+               2500 * 1000, 0, 0, FALSE,
                NULL, NULL, NULL,
        },
        {
@@ -228,7 +228,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 6, cmdset_gwinstek, ARRAY_AND_SIZE(mqopts_gwinstek_gdm8200a),
                scpi_dmm_get_meas_gwinstek,
                ARRAY_AND_SIZE(devopts_generic),
-               2500 * 1000, 0, FALSE,
+               2500 * 1000, 0, 0, FALSE,
                NULL, NULL, NULL,
        },
        {
@@ -236,7 +236,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 6, cmdset_gwinstek_906x, ARRAY_AND_SIZE(mqopts_gwinstek_gdm906x),
                scpi_dmm_get_meas_agilent,
                ARRAY_AND_SIZE(devopts_generic),
-               0, 0, FALSE,
+               0, 0, 0, FALSE,
                NULL, NULL, NULL,
        },
        {
@@ -244,7 +244,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 6, cmdset_gwinstek_906x, ARRAY_AND_SIZE(mqopts_gwinstek_gdm906x),
                scpi_dmm_get_meas_agilent,
                ARRAY_AND_SIZE(devopts_generic),
-               0, 0, FALSE,
+               0, 0, 0, FALSE,
                NULL, NULL, NULL,
        },
        {
@@ -253,7 +253,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                scpi_dmm_get_meas_agilent,
                ARRAY_AND_SIZE(devopts_generic),
                /* 34401A: typ. 1020ms for AC readings (default is 1000ms). */
-               1500 * 1000, 0, FALSE,
+               1500 * 1000, 0, 0, FALSE,
                NULL, NULL, NULL,
        },
        {
@@ -261,7 +261,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 6, cmdset_agilent, ARRAY_AND_SIZE(mqopts_agilent_34405a),
                scpi_dmm_get_meas_agilent,
                ARRAY_AND_SIZE(devopts_generic_range),
-               0, 0, FALSE,
+               0, 0, 0, FALSE,
                scpi_dmm_get_range_text, scpi_dmm_set_range_from_text, NULL,
        },
        {
@@ -269,7 +269,7 @@ SR_PRIV const struct scpi_dmm_model models[] = {
                1, 5, cmdset_owon, ARRAY_AND_SIZE(mqopts_owon_xdm2041),
                scpi_dmm_get_meas_gwinstek,
                ARRAY_AND_SIZE(devopts_generic),
-               0, 1e9, TRUE,
+               0, 0, 1e9, TRUE,
                NULL, NULL, NULL,
        },
 };

diff --git a/src/hardware/scpi-dmm/protocol.c b/src/hardware/scpi-dmm/protocol.c
index 1a967358907099261627d4d364c032b6329027ac..f413fcd730fbcaad79d58be38fbc2de3ed74d4fd 100644 (file)
--- a/src/hardware/scpi-dmm/protocol.c
+++ b/src/hardware/scpi-dmm/protocol.c
@@ -150,6 +150,8 @@ SR_PRIV int scpi_dmm_set_mq(const struct sr_dev_inst *sdi,
        ret = sr_scpi_send(sdi->conn, command, mode);
        if (ret != SR_OK)
                return ret;
+       if (item->drv_flags & FLAG_CONF_DELAY)
+               g_usleep(devc->model->conf_delay_us);
 
        return SR_OK;
 }
@@ -241,6 +243,8 @@ SR_PRIV int scpi_dmm_set_range_from_text(const struct sr_dev_inst *sdi,
                item->scpi_func_setup, is_auto ? "AUTO" : range);
        if (ret != SR_OK)
                return ret;
+       if (item->drv_flags & FLAG_CONF_DELAY)
+               g_usleep(devc->model->conf_delay_us);
 
        return SR_OK;
 }

diff --git a/src/hardware/scpi-dmm/protocol.h b/src/hardware/scpi-dmm/protocol.h
index 04b8e683155bde2516d0113d58f63110f8a96419..0864196c44a365c7a40a35d474d54c02e6a1506c 100644 (file)
--- a/src/hardware/scpi-dmm/protocol.h
+++ b/src/hardware/scpi-dmm/protocol.h
@@ -58,6 +58,7 @@ struct mqopt_item {
 #define NO_DFLT_PREC   -99
 #define FLAGS_NONE     0
 #define FLAG_NO_RANGE  (1 << 0)
+#define FLAG_CONF_DELAY        (1 << 1)
 
 struct scpi_dmm_model {
        const char *vendor;
@@ -71,6 +72,7 @@ struct scpi_dmm_model {
        const uint32_t *devopts;
        size_t devopts_size;
        unsigned int read_timeout_us; /* If zero, use default from src/scpi/scpi.c. */
+       unsigned int conf_delay_us;
        float infinity_limit; /* If zero, use default from protocol.c */
        gboolean check_opc;
        const char *(*get_range_text)(const struct sr_dev_inst *sdi);