libsigrok/src/hardware/scpi-dmm/protocol.c

687 lines
17 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2018 Gerhard Sittig <gerhard.sittig@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
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <math.h>
#include <string.h>
#include "protocol.h"
#define WITH_CMD_DELAY 0 /* TODO See which devices need delays. */
SR_PRIV void scpi_dmm_cmd_delay(struct sr_scpi_dev_inst *scpi)
{
if (WITH_CMD_DELAY)
g_usleep(WITH_CMD_DELAY * 1000);
if (!scpi->no_opc_command)
sr_scpi_get_opc(scpi);
}
SR_PRIV const struct mqopt_item *scpi_dmm_lookup_mq_number(
const struct sr_dev_inst *sdi, enum sr_mq mq, enum sr_mqflag flag)
{
struct dev_context *devc;
size_t i;
const struct mqopt_item *item;
devc = sdi->priv;
for (i = 0; i < devc->model->mqopt_size; i++) {
item = &devc->model->mqopts[i];
if (item->mq != mq || item->mqflag != flag)
continue;
return item;
}
return NULL;
}
SR_PRIV const struct mqopt_item *scpi_dmm_lookup_mq_text(
const struct sr_dev_inst *sdi, const char *text)
{
struct dev_context *devc;
size_t i;
const struct mqopt_item *item;
devc = sdi->priv;
for (i = 0; i < devc->model->mqopt_size; i++) {
item = &devc->model->mqopts[i];
if (!item->scpi_func_query || !item->scpi_func_query[0])
continue;
if (!g_str_has_prefix(text, item->scpi_func_query))
continue;
return item;
}
return NULL;
}
SR_PRIV int scpi_dmm_get_mq(const struct sr_dev_inst *sdi,
enum sr_mq *mq, enum sr_mqflag *flag, char **rsp,
const struct mqopt_item **mqitem)
{
struct dev_context *devc;
const char *command;
char *response;
const char *have;
int ret;
const struct mqopt_item *item;
devc = sdi->priv;
if (mq)
*mq = 0;
if (flag)
*flag = 0;
if (rsp)
*rsp = NULL;
if (mqitem)
*mqitem = NULL;
scpi_dmm_cmd_delay(sdi->conn);
command = sr_scpi_cmd_get(devc->cmdset, DMM_CMD_QUERY_FUNC);
if (!command || !*command)
return SR_ERR_NA;
response = NULL;
ret = sr_scpi_get_string(sdi->conn, command, &response);
if (ret != SR_OK)
return ret;
if (!response || !*response)
return SR_ERR_NA;
have = response;
if (*have == '"')
have++;
ret = SR_ERR_NA;
item = scpi_dmm_lookup_mq_text(sdi, have);
if (item) {
if (mq)
*mq = item->mq;
if (flag)
*flag = item->mqflag;
if (mqitem)
*mqitem = item;
ret = SR_OK;
}
if (rsp) {
*rsp = response;
response = NULL;
}
g_free(response);
return ret;
}
SR_PRIV int scpi_dmm_set_mq(const struct sr_dev_inst *sdi,
enum sr_mq mq, enum sr_mqflag flag)
{
struct dev_context *devc;
const struct mqopt_item *item;
const char *mode, *command;
int ret;
devc = sdi->priv;
item = scpi_dmm_lookup_mq_number(sdi, mq, flag);
if (!item)
return SR_ERR_NA;
mode = item->scpi_func_setup;
command = sr_scpi_cmd_get(devc->cmdset, DMM_CMD_SETUP_FUNC);
scpi_dmm_cmd_delay(sdi->conn);
ret = sr_scpi_send(sdi->conn, command, mode);
if (ret != SR_OK)
return ret;
return SR_OK;
}
SR_PRIV int scpi_dmm_get_meas_agilent(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;
char **fields;
size_t count;
char prec_text[20];
const struct mqopt_item *item;
int prec_exp;
const char *command;
char *response;
gboolean use_double;
int sig_digits, val_exp;
int digits;
enum sr_unit unit;
double limit;
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;
}
/*
* Get the last comma separated field of the function query
* response, or fallback to the model's default precision for
* the current function. This copes with either of these cases:
* VOLT +1.00000E-01,+1.00000E-06
* DIOD
* TEMP THER,5000,+1.00000E+00,+1.00000E-01
*/
p = sr_scpi_unquote_string(mode_response);
fields = g_strsplit(p, ",", 0);
count = g_strv_length(fields);
if (count >= 2) {
snprintf(prec_text, sizeof(prec_text),
"%s", fields[count - 1]);
p = prec_text;
} else if (!item) {
p = NULL;
} else if (item->default_precision == NO_DFLT_PREC) {
p = NULL;
} else {
snprintf(prec_text, sizeof(prec_text),
"1e%d", item->default_precision);
p = prec_text;
}
g_strfreev(fields);
/*
* Need to extract the exponent value ourselves, since a strtod()
* call will "eat" the exponent, too. Strip space, strip sign,
* strip float number (without! exponent), check for exponent
* and get exponent value. Accept absence of Esnn suffixes.
*/
while (p && *p && g_ascii_isspace(*p))
p++;
if (p && *p && (*p == '+' || *p == '-'))
p++;
while (p && *p && g_ascii_isdigit(*p))
p++;
if (p && *p && *p == '.')
p++;
while (p && *p && g_ascii_isdigit(*p))
p++;
ret = SR_OK;
if (!p || !*p)
prec_exp = 0;
else if (*p != 'e' && *p != 'E')
ret = SR_ERR_DATA;
else
ret = sr_atoi(++p, &prec_exp);
g_free(mode_response);
if (ret != SR_OK)
return ret;
/*
* Get the measurement value. Make sure to strip trailing space
* or else number conversion may fail in fatal ways. Detect OL
* conditions. Determine the measurement's precision: Count the
* number of significant digits before the period, and get the
* exponent's value.
*
* The text presentation of values is like this:
* +1.09450000E-01
* Skip space/sign, count digits before the period, skip to the
* exponent, get exponent value.
*
* TODO Can sr_parse_rational() return the exponent for us? In
* addition to providing a precise rational value instead of a
* float that's an approximation of the received value? Can the
* 'analog' struct that we fill in carry rationals?
*
* Use double precision FP here during conversion. Optionally
* downgrade to single precision later to reduce the amount of
* logged information.
*/
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;
limit = 9e37;
if (info->d_value > +limit) {
info->d_value = +INFINITY;
} else if (info->d_value < -limit) {
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;
/*
* TODO Come up with the most appropriate 'digits' calculation.
* This implementation assumes that either the device provides
* the resolution with the query for the meter's function, or
* the driver uses a fallback text pretending the device had
* provided it. This works with supported Agilent devices.
*
* An alternative may be to assume a given digits count which
* depends on the device, and adjust that count based on the
* value's significant digits and exponent. But this approach
* fails if devices change their digits count depending on
* modes or user requests, and also fails when e.g. devices
* with "100000 counts" can provide values between 100000 and
* 120000 in either 4 or 5 digits modes, depending on the most
* recent trend of the values. This less robust approach should
* only be taken if the mode inquiry won't yield the resolution
* (as e.g. DIOD does on 34405A, though we happen to know the
* fixed resolution for this very mode on this very model).
*
* For now, let's keep the prepared code path for the second
* approach in place, should some Agilent devices need it yet
* benefit from re-using most of the remaining acquisition
* routine.
*/
#if 1
digits = -prec_exp;
#else
digits = devc->model->digits;
digits -= sig_digits;
digits -= val_exp;
#endif
/*
* 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->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:
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;
}
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;
double limit;
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;
limit = 9e37;
if (devc->model->infinity_limit != 0.0)
limit = devc->model->infinity_limit;
if (info->d_value >= +limit) {
info->d_value = +INFINITY;
} else if (info->d_value <= -limit) {
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. */
limit = 1.2e8;
if (strcmp(devc->model->model, "GDM8255A") == 0)
limit = 1.99999e8;
if (info->d_value >= limit)
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 result of the optional
* precision reading which was done at acquisition start.
* The GW-Instek manual gives the following information
* regarding the 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 (g_str_has_prefix(devc->precision, "Slow"))
digits = 6;
else if (g_str_has_prefix(devc->precision, "Mid"))
digits = 5;
else if (g_str_has_prefix(devc->precision, "Fast"))
digits = 4;
else
sr_info("Unknown precision: '%s'", 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->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)
{
struct sr_dev_inst *sdi;
struct sr_scpi_dev_inst *scpi;
struct dev_context *devc;
struct scpi_dmm_acq_info *info;
gboolean sent_sample;
size_t ch;
struct sr_channel *channel;
int ret;
(void)fd;
(void)revents;
sdi = cb_data;
if (!sdi)
return TRUE;
scpi = sdi->conn;
devc = sdi->priv;
if (!scpi || !devc)
return TRUE;
info = &devc->run_acq_info;
sent_sample = FALSE;
ret = SR_OK;
for (ch = 0; ch < devc->num_channels; ch++) {
/* Check the channel's enabled status. */
channel = g_slist_nth_data(sdi->channels, ch);
if (!channel->enabled)
continue;
/*
* Prepare an analog measurement value. Note that digits
* will get updated later.
*/
info->packet.type = SR_DF_ANALOG;
info->packet.payload = &info->analog[ch];
sr_analog_init(&info->analog[ch], &info->encoding[ch],
&info->meaning[ch], &info->spec[ch], 0);
/* Just check OPC before sending another request. */
scpi_dmm_cmd_delay(sdi->conn);
/*
* Have the model take and interpret a measurement. Lack
* of support is pointless, failed retrieval/conversion
* is considered fatal. The routine will fill in the
* 'analog' details, except for channel name and sample
* count (assume one value per channel).
*
* Note that non-zero non-negative return codes signal
* that the channel's data shell get skipped in this
* iteration over the channels. This copes with devices
* or modes where channels may provide data at different
* rates.
*/
if (!devc->model->get_measurement) {
ret = SR_ERR_NA;
break;
}
ret = devc->model->get_measurement(sdi, ch);
if (ret > 0)
continue;
if (ret != SR_OK)
break;
/* Send the packet that was filled in by the model's routine. */
info->analog[ch].num_samples = 1;
info->analog[ch].meaning->channels = g_slist_append(NULL, channel);
sr_session_send(sdi, &info->packet);
g_slist_free(info->analog[ch].meaning->channels);
sent_sample = TRUE;
}
if (sent_sample)
sr_sw_limits_update_samples_read(&devc->limits, 1);
if (ret != SR_OK) {
/* Stop acquisition upon communication or data errors. */
sr_dev_acquisition_stop(sdi);
return TRUE;
}
if (sr_sw_limits_check(&devc->limits))
sr_dev_acquisition_stop(sdi);
return TRUE;
}