scpi-dmm: Add support for GW-Instek 8200A series bench multimeters.

- Add support for GDM-8251A and GDM-8255A DMMs.

src/hardware/scpi-dmm/api.c

@@ -80,6 +80,17 @@ static const struct scpi_command cmdset_hp[] = {
 	ALL_ZERO,
 };
 
+static const struct scpi_command cmdset_gwinstek[] = {
+	{ DMM_CMD_SETUP_REMOTE, "SYST:REM", },
+	{ DMM_CMD_SETUP_FUNC, "CONF:%s", },
+	{ DMM_CMD_QUERY_FUNC, "CONF:STAT:FUNC?", },
+	{ DMM_CMD_START_ACQ, "*CLS;SYST:REM", },
+	{ DMM_CMD_STOP_ACQ, "SYST:LOC", },
+	{ DMM_CMD_QUERY_VALUE, "VAL1?", },
+	{ DMM_CMD_QUERY_PREC, "SENS:DET:RATE?", },
+	ALL_ZERO,
+};
+
 static const struct mqopt_item mqopts_agilent_34405a[] = {
 	{ SR_MQ_VOLTAGE, SR_MQFLAG_DC, "VOLT:DC", "VOLT ", NO_DFLT_PREC, },
 	{ SR_MQ_VOLTAGE, SR_MQFLAG_AC, "VOLT:AC", "VOLT:AC ", NO_DFLT_PREC, },
@@ -106,6 +117,23 @@ static const struct mqopt_item mqopts_agilent_34401a[] = {
 	{ SR_MQ_TIME, 0, "PER", "PER ", NO_DFLT_PREC, },
 };
 
+static const struct mqopt_item mqopts_gwinstek_gdm8200a[] = {
+	{ SR_MQ_VOLTAGE, SR_MQFLAG_DC, "VOLT:DC", "01", NO_DFLT_PREC, },
+	{ SR_MQ_VOLTAGE, SR_MQFLAG_AC, "VOLT:AC", "02", NO_DFLT_PREC, },
+	{ SR_MQ_CURRENT, SR_MQFLAG_DC, "CURR:DC", "03", NO_DFLT_PREC, },
+	{ SR_MQ_CURRENT, SR_MQFLAG_AC, "CURR:AC", "04", NO_DFLT_PREC, },
+	{ SR_MQ_CURRENT, SR_MQFLAG_DC, "CURR:DC", "05", NO_DFLT_PREC, }, /* mA */
+	{ SR_MQ_CURRENT, SR_MQFLAG_AC, "CURR:AC", "06", NO_DFLT_PREC, }, /* mA */
+	{ SR_MQ_RESISTANCE, 0, "RES", "07", NO_DFLT_PREC, },
+	{ SR_MQ_RESISTANCE, SR_MQFLAG_FOUR_WIRE, "FRES", "16", NO_DFLT_PREC, },
+	{ SR_MQ_CONTINUITY, 0, "CONT", "13", -1, },
+	{ SR_MQ_VOLTAGE, SR_MQFLAG_DC | SR_MQFLAG_DIODE, "DIOD", "17", -4, },
+	{ SR_MQ_TEMPERATURE, 0, "TEMP", "09", NO_DFLT_PREC, }, /* Celsius */
+	{ SR_MQ_TEMPERATURE, 0, "TEMP", "15", NO_DFLT_PREC, }, /* Fahrenheit */
+	{ SR_MQ_FREQUENCY, 0, "FREQ", "08", NO_DFLT_PREC, },
+	{ SR_MQ_TIME, 0, "PER", "14", NO_DFLT_PREC, },
+};
+
 SR_PRIV const struct scpi_dmm_model models[] = {
 	{
 		"Agilent", "34405A",
@@ -136,6 +164,20 @@ SR_PRIV const struct scpi_dmm_model models[] = {
 		/* 34401A: typ. 1020ms for AC readings (default is 1000ms). */
 		1000 * 1500,
 	},
+	{
+		"GW", "GDM8251A",
+		1, 6, cmdset_gwinstek, ARRAY_AND_SIZE(mqopts_gwinstek_gdm8200a),
+		scpi_dmm_get_meas_gwinstek,
+		ARRAY_AND_SIZE(devopts_generic),
+		1000 * 2500,
+	},
+	{
+		"GW", "GDM8255A",
+		1, 6, cmdset_gwinstek, ARRAY_AND_SIZE(mqopts_gwinstek_gdm8200a),
+		scpi_dmm_get_meas_gwinstek,
+		ARRAY_AND_SIZE(devopts_generic),
+		1000 * 2500,
+	},
 };
 
 static const struct scpi_dmm_model *is_compatible(const char *vendor, const char *model)
@@ -197,6 +239,7 @@ static struct sr_dev_inst *probe_device(struct sr_scpi_dev_inst *scpi)
 	devc->num_channels = model->num_channels;
 	devc->cmdset = model->cmdset;
 	devc->model = model;
+	devc->precision = NULL;
 
 	for (i = 0; i < devc->num_channels; i++) {
 		channel_name = g_strdup_printf("P%zu", i + 1);
@@ -347,6 +390,7 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 	int ret;
 	const struct mqopt_item *item;
 	const char *command;
+	char *response;
 
 	scpi = sdi->conn;
 	devc = sdi->priv;
@@ -356,6 +400,26 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 	if (ret != SR_OK)
 		return ret;
 
+	/*
+	 * Query for current precision if DMM supports the command
+	 */
+	command = sr_scpi_cmd_get(devc->cmdset, DMM_CMD_QUERY_PREC);
+	if (command && *command) {
+		scpi_dmm_cmd_delay(scpi);
+		ret = sr_scpi_get_string(scpi, command, &response);
+		if (ret == SR_OK) {
+			g_strstrip(response);
+			if (devc->precision)
+				g_free(devc->precision);
+			devc->precision=g_strdup(response);
+			g_free(response);
+			sr_dbg("%s: Precision: '%s'", __func__, devc->precision);
+		} else {
+			sr_info("%s: Precision query ('%s') failed: %d",
+				__func__, command, ret);
+		}
+	}
+
 	command = sr_scpi_cmd_get(devc->cmdset, DMM_CMD_START_ACQ);
 	if (command && *command) {
 		scpi_dmm_cmd_delay(scpi);
@@ -395,6 +459,11 @@ static int dev_acquisition_stop(struct sr_dev_inst *sdi)
 
 	std_session_send_df_end(sdi);
 
+	if (devc->precision) {
+		g_free(devc->precision);
+		devc->precision = NULL;
+	}
+
 	return SR_OK;
 }
 

src/hardware/scpi-dmm/protocol.c

@@ -398,6 +398,215 @@ SR_PRIV int scpi_dmm_get_meas_agilent(const struct sr_dev_inst *sdi, size_t ch)
 	return SR_OK;
 }
 
+SR_PRIV int scpi_dmm_get_meas_gwinstek(const struct sr_dev_inst *sdi, size_t ch)
+{
+	struct sr_scpi_dev_inst *scpi;
+	struct dev_context *devc;
+	struct scpi_dmm_acq_info *info;
+	struct sr_datafeed_analog *analog;
+	int ret;
+	enum sr_mq mq;
+	enum sr_mqflag mqflag;
+	char *mode_response;
+	const char *p;
+	const struct mqopt_item *item;
+	const char *command;
+	char *response;
+	gboolean use_double;
+	int sig_digits, val_exp;
+	int digits;
+	enum sr_unit unit;
+	int mmode;
+
+	scpi = sdi->conn;
+	devc = sdi->priv;
+	info = &devc->run_acq_info;
+	analog = &info->analog[ch];
+
+	/*
+	 * Get the meter's current mode, keep the response around.
+	 * Skip the measurement if the mode is uncertain.
+	 */
+	ret = scpi_dmm_get_mq(sdi, &mq, &mqflag, &mode_response, &item);
+	if (ret != SR_OK) {
+		g_free(mode_response);
+		return ret;
+	}
+	if (!mode_response)
+		return SR_ERR;
+	if (!mq) {
+		g_free(mode_response);
+		return +1;
+	}
+	mmode = atoi(mode_response);
+	g_free(mode_response);
+
+	/*
+	 * Get the current reading from the meter.
+	 */
+	scpi_dmm_cmd_delay(scpi);
+	command = sr_scpi_cmd_get(devc->cmdset, DMM_CMD_QUERY_VALUE);
+	if (!command || !*command)
+		return SR_ERR_NA;
+	scpi_dmm_cmd_delay(scpi);
+	ret = sr_scpi_get_string(scpi, command, &response);
+	if (ret != SR_OK)
+		return ret;
+	g_strstrip(response);
+	use_double = devc->model->digits > 6;
+	ret = sr_atod_ascii(response, &info->d_value);
+	if (ret != SR_OK) {
+		g_free(response);
+		return ret;
+	}
+	if (!response)
+		return SR_ERR;
+	if (info->d_value > +9e37) {
+		info->d_value = +INFINITY;
+	} else if (info->d_value < -9e37) {
+		info->d_value = -INFINITY;
+	} else {
+		p = response;
+		while (p && *p && g_ascii_isspace(*p))
+			p++;
+		if (p && *p && (*p == '-' || *p == '+'))
+			p++;
+		sig_digits = 0;
+		while (p && *p && g_ascii_isdigit(*p)) {
+			sig_digits++;
+			p++;
+		}
+		if (p && *p && *p == '.')
+			p++;
+		while (p && *p && g_ascii_isdigit(*p))
+			p++;
+		ret = SR_OK;
+		if (!p || !*p)
+			val_exp = 0;
+		else if (*p != 'e' && *p != 'E')
+			ret = SR_ERR_DATA;
+		else
+			ret = sr_atoi(++p, &val_exp);
+	}
+	g_free(response);
+	if (ret != SR_OK)
+		return ret;
+
+	/*
+	 * Make sure we report "INFINITY" when meter displays "0L"
+	 */
+	switch (mmode) {
+	case 7:
+	case 16:
+		/* in resitance modes 0L reads as 1.20000E8 or 1.99999E8 */
+		if (!strncmp(devc->model->model,"GDM8255A",8)) {
+			if (info->d_value >= 1.99999e8)
+				info->d_value = +INFINITY;
+		} else {
+			if (info->d_value >= 1.2e8)
+				info->d_value = +INFINITY;
+		}
+		break;
+	case 13:
+		/* In continuity mode 0L reads as 1.20000E3 */
+		if (info->d_value >= 1.2e3)
+			info->d_value = +INFINITY;
+		break;
+	case 17:
+		/* in diode mode 0L reads as 1.00000E0 */
+		if (info->d_value == 1.0e0)
+			info->d_value = +INFINITY;
+		break;
+	}
+
+	/*
+	 * Calculate 'digits' based on the precision reading result
+	 * done during start of acquisition.
+	 *
+	 * GW-Instek manual gives following info regarding resolution:
+	 *
+	 * Type                  Digit
+	 * --------------------  ------------
+	 * Slow                  5 1/2
+	 * Medium                4 1/2
+	 * Fast                  3 1/2
+	 *
+	 */
+
+	digits = devc->model->digits;
+	if (devc->precision && *devc->precision) {
+		if (!strncmp(devc->precision, "Slow", 4))
+			digits = 6;
+		else if (!strncmp(devc->precision, "Mid", 3))
+			digits = 5;
+		else if (!strncmp(devc->precision, "Fast", 4))
+			digits = 4;
+		else
+			sr_info("%s: Unknown precision: '%s'",
+				__func__, devc->precision);
+	}
+
+	/*
+	 * Fill in the 'analog' description: value, encoding, meaning.
+	 * Callers will fill in the sample count, and channel name,
+	 * and will send out the packet.
+	 */
+	if (use_double) {
+		analog->data = &info->d_value;
+		analog->encoding->unitsize = sizeof(info->d_value);
+	} else {
+		info->f_value = info->d_value;
+		analog->data = &info->f_value;
+		analog->encoding->unitsize = sizeof(info->f_value);
+	}
+	analog->encoding->is_float = TRUE;
+#ifdef WORDS_BIGENDIAN
+	analog->encoding->is_bigendian = TRUE;
+#else
+	analog->encoding->is_bigendian = FALSE;
+#endif
+	analog->encoding->digits = digits;
+	analog->meaning->mq = mq;
+	analog->meaning->mqflags = mqflag;
+	switch (mq) {
+	case SR_MQ_VOLTAGE:
+		unit = SR_UNIT_VOLT;
+		break;
+	case SR_MQ_CURRENT:
+		unit = SR_UNIT_AMPERE;
+		break;
+	case SR_MQ_RESISTANCE:
+	case SR_MQ_CONTINUITY:
+		unit = SR_UNIT_OHM;
+		break;
+	case SR_MQ_CAPACITANCE:
+		unit = SR_UNIT_FARAD;
+		break;
+	case SR_MQ_TEMPERATURE:
+		switch (mmode) {
+		case 15:
+			unit = SR_UNIT_FAHRENHEIT;
+			break;
+		case 9:
+		default:
+			unit = SR_UNIT_CELSIUS;
+		}
+		break;
+	case SR_MQ_FREQUENCY:
+		unit = SR_UNIT_HERTZ;
+		break;
+	case SR_MQ_TIME:
+		unit = SR_UNIT_SECOND;
+		break;
+	default:
+		return SR_ERR_NA;
+	}
+	analog->meaning->unit = unit;
+	analog->spec->spec_digits = digits;
+
+	return SR_OK;
+}
+
 /* Strictly speaking this is a timer controlled poll routine. */
 SR_PRIV int scpi_dmm_receive_data(int fd, int revents, void *cb_data)
 {

src/hardware/scpi-dmm/protocol.h

@@ -83,6 +83,7 @@ struct dev_context {
 		struct sr_analog_meaning meaning[SCPI_DMM_MAX_CHANNELS];
 		struct sr_analog_spec spec[SCPI_DMM_MAX_CHANNELS];
 	} run_acq_info;
+	gchar *precision;
 };
 
 SR_PRIV void scpi_dmm_cmd_delay(struct sr_scpi_dev_inst *scpi);
@@ -96,6 +97,7 @@ SR_PRIV int scpi_dmm_get_mq(const struct sr_dev_inst *sdi,
 SR_PRIV int scpi_dmm_set_mq(const struct sr_dev_inst *sdi,
 	enum sr_mq mq, enum sr_mqflag flag);
 SR_PRIV int scpi_dmm_get_meas_agilent(const struct sr_dev_inst *sdi, size_t ch);
+SR_PRIV int scpi_dmm_get_meas_gwinstek(const struct sr_dev_inst *sdi, size_t ch);
 SR_PRIV int scpi_dmm_receive_data(int fd, int revents, void *cb_data);
 
 #endif