*/
#include <config.h>
+#include <math.h>
+#include <scpi.h>
#include "protocol.h"
+static int set_mq_volt(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
+static int set_mq_amp(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
+static int set_mq_ohm(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
+
+/*
+ * The source for the frequency measurement can be either AC voltage, AC+DC
+ * voltage, AC current, or AC+DC current. Configuring this is not yet
+ * supported. For details, see "FSOURCE" command.
+ * The set_mode function is optional and can be set to NULL, but in that case
+ * a cmd string must be provided.
+ */
+static const struct {
+ enum sr_mq mq;
+ enum sr_unit unit;
+ const char *cmd;
+ int (*set_mode)(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
+} sr_mq_to_cmd_map[] = {
+ { SR_MQ_VOLTAGE, SR_UNIT_VOLT, "DCV", set_mq_volt },
+ { SR_MQ_CURRENT, SR_UNIT_AMPERE, "DCI", set_mq_amp },
+ { SR_MQ_RESISTANCE, SR_UNIT_OHM, "OHM", set_mq_ohm },
+ { SR_MQ_FREQUENCY, SR_UNIT_HERTZ, "FREQ", NULL },
+};
+
+static const struct rear_card_info rear_card_parameters[] = {
+ {
+ .type = REAR_TERMINALS,
+ .card_id = 0,
+ .name = "Rear terminals",
+ .cg_name = "rear",
+ .num_channels = 1,
+ }, {
+ .type = HP_44491A,
+ .card_id = 44491,
+ .name = "44491A Armature Relay Multiplexer",
+ .cg_name = "44491a",
+ .num_channels = 14,
+ }, {
+ .type = HP_44492A,
+ .card_id = 44492,
+ .name = "44492A Reed Relay Multiplexer",
+ .cg_name = "44492a",
+ .num_channels = 10,
+ }
+};
+
+static int send_mq_ac_dc(struct sr_scpi_dev_inst *scpi, const char *mode,
+ enum sr_mqflag flags)
+{
+ const char *ac_flag, *dc_flag;
+
+ if (flags & ~(SR_MQFLAG_AC | SR_MQFLAG_DC))
+ return SR_ERR_NA;
+
+ ac_flag = (flags & SR_MQFLAG_AC) ? "AC" : "";
+ dc_flag = "";
+ /* Must specify DC measurement when AC flag is not given. */
+ if ((flags & SR_MQFLAG_DC) || !(flags & SR_MQFLAG_AC))
+ dc_flag = "DC";
+
+ return sr_scpi_send(scpi, "%s%s%s", ac_flag, dc_flag, mode);
+}
+
+static int set_mq_volt(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
+{
+ return send_mq_ac_dc(scpi, "V", flags);
+}
+
+static int set_mq_amp(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
+{
+ return send_mq_ac_dc(scpi, "I", flags);
+}
+
+static int set_mq_ohm(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
+{
+ const char *ohm_flag;
+
+ if (flags & ~(SR_MQFLAG_FOUR_WIRE))
+ return SR_ERR_NA;
+
+ ohm_flag = (flags & SR_MQFLAG_FOUR_WIRE) ? "F" : "";
+ return sr_scpi_send(scpi, "OHM%s", ohm_flag);
+}
+
+SR_PRIV int hp_3457a_set_mq(const struct sr_dev_inst *sdi, enum sr_mq mq,
+ enum sr_mqflag mq_flags)
+{
+ int ret;
+ size_t i;
+ 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)
+ return SR_OK;
+
+ for (i = 0; i < ARRAY_SIZE(sr_mq_to_cmd_map); i++) {
+ if (sr_mq_to_cmd_map[i].mq != mq)
+ continue;
+ if (sr_mq_to_cmd_map[i].set_mode) {
+ ret = sr_mq_to_cmd_map[i].set_mode(scpi, mq_flags);
+ } else {
+ ret = sr_scpi_send(scpi, sr_mq_to_cmd_map[i].cmd);
+ }
+ if (ret == SR_OK) {
+ devc->measurement_mq = sr_mq_to_cmd_map[i].mq;
+ devc->measurement_mq_flags = mq_flags;
+ devc->measurement_unit = sr_mq_to_cmd_map[i].unit;
+ }
+ return ret;
+ }
+
+ return SR_ERR_NA;
+}
+
+SR_PRIV const struct rear_card_info *hp_3457a_probe_rear_card(struct sr_scpi_dev_inst *scpi)
+{
+ size_t i;
+ float card_fval;
+ unsigned int card_id;
+ const struct rear_card_info *rear_card = NULL;
+
+ if (sr_scpi_get_float(scpi, "OPT?", &card_fval) != SR_OK)
+ return NULL;
+
+ card_id = (unsigned int)card_fval;
+
+ for (i = 0; i < ARRAY_SIZE(rear_card_parameters); i++) {
+ if (rear_card_parameters[i].card_id == card_id) {
+ rear_card = rear_card_parameters + i;
+ break;
+ }
+ }
+
+ if (!rear_card)
+ return NULL;
+
+ sr_info("Found %s.", rear_card->name);
+
+ return rear_card;
+}
+
+SR_PRIV int hp_3457a_set_nplc(const struct sr_dev_inst *sdi, float nplc)
+{
+ int ret;
+ struct sr_scpi_dev_inst *scpi = sdi->conn;
+ struct dev_context *devc = sdi->priv;
+
+ if ((nplc < 1E-6) || (nplc > 100))
+ return SR_ERR_ARG;
+
+ /* Only need one digit of precision here. */
+ ret = sr_scpi_send(scpi, "NPLC %.0E", nplc);
+
+ /*
+ * The instrument only has a few valid NPLC setting, so get back the
+ * one which was selected.
+ */
+ sr_scpi_get_float(scpi, "NPLC?", &devc->nplc);
+
+ return ret;
+}
+
+SR_PRIV int hp_3457a_select_input(const struct sr_dev_inst *sdi,
+ enum channel_conn loc)
+{
+ int ret;
+ struct sr_scpi_dev_inst *scpi = sdi->conn;
+ struct dev_context *devc = sdi->priv;
+
+ if (devc->input_loc == loc)
+ return SR_OK;
+
+ ret = sr_scpi_send(scpi, "TERM %s", (loc == CONN_FRONT) ? "FRONT": "REAR");
+ if (ret == SR_OK)
+ devc->input_loc = loc;
+
+ return ret;
+}
+
+SR_PRIV int hp_3457a_send_scan_list(const struct sr_dev_inst *sdi,
+ unsigned int *channels, size_t len)
+{
+ size_t i;
+ char chan[16], list_str[64] = "";
+
+ for (i = 0; i < len; i++) {
+ g_snprintf(chan, sizeof(chan), ",%u", channels[i]);
+ g_strlcat(list_str, chan, sizeof(list_str));
+ }
+
+ return sr_scpi_send(sdi->conn, "SLIST %s", list_str);
+}
+
+/* HIRES register only contains valid data with 10 or more powerline cycles. */
+static int is_highres_enabled(struct dev_context *devc)
+{
+ return (devc->nplc >= 10.0);
+}
+
+static void activate_next_channel(struct dev_context *devc)
+{
+ GSList *list_elem;
+ struct sr_channel *chan;
+
+ list_elem = g_slist_find(devc->active_channels, devc->current_channel);
+ if (list_elem)
+ list_elem = list_elem->next;
+ if (!list_elem)
+ list_elem = devc->active_channels;
+
+ chan = list_elem->data;
+
+ devc->current_channel = chan;
+}
+
+static void retrigger_measurement(struct sr_scpi_dev_inst *scpi,
+ struct dev_context *devc)
+{
+ sr_scpi_send(scpi, "?");
+ devc->acq_state = ACQ_TRIGGERED_MEASUREMENT;
+}
+
+static void request_hires(struct sr_scpi_dev_inst *scpi,
+ struct dev_context *devc)
+{
+ sr_scpi_send(scpi, "RMATH HIRES");
+ devc->acq_state = ACQ_REQUESTED_HIRES;
+}
+
+static void request_range(struct sr_scpi_dev_inst *scpi,
+ struct dev_context *devc)
+{
+ sr_scpi_send(scpi, "RANGE?");
+ devc->acq_state = ACQ_REQUESTED_RANGE;
+}
+
+static void request_current_channel(struct sr_scpi_dev_inst *scpi,
+ struct dev_context *devc)
+{
+ sr_scpi_send(scpi, "CHAN?");
+ devc->acq_state = ACQ_REQUESTED_CHANNEL_SYNC;
+}
+
+/*
+ * Calculate the number of leading zeroes in the measurement.
+ *
+ * Depending on the range and measurement, a reading may not have eight digits
+ * of resolution. For example, on a 30V range:
+ * : 10.000000 V has 8 significant digits
+ * : 9.999999 V has 7 significant digits
+ * : 0.999999 V has 6 significant digits
+ *
+ * The number of significant digits is determined based on the range in which
+ * the measurement was taken:
+ * 1. By taking the base 10 logarithm of the range, and converting that to
+ * an integer, we can get the minimum reading which has a full resolution
+ * reading. Raising 10 to the integer power gives the full resolution.
+ * Ex: For 30 V range, a full resolution reading is 10.000000.
+ * 2. A ratio is taken between the full resolution reading and the
+ * measurement. Since the full resolution reading is a power of 10,
+ * for every leading zero, this ratio will be slightly higher than a
+ * power of 10. For example, for 10 V full resolution:
+ * : 10.000000 V, ratio = 1.0000000
+ * : 9.999999 V, ratio = 1.0000001
+ * : 0.999999 V, ratio = 10.000001
+ * 3. The ratio is rounded up to prevent loss of precision in the next step.
+ * 4. The base 10 logarithm of the ratio is taken, then rounded up. This
+ * gives the number of leading zeroes in the measurement.
+ * For example, for 10 V full resolution:
+ * : 10.000000 V, ceil(1.0000000) = 1, log10 = 0.00; 0 leading zeroes
+ * : 9.999999 V, ceil(1.0000001) = 2, log10 = 0.30; 1 leading zero
+ * : 0.999999 V, ceil(10.000001) = 11, log10 = 1.04, 2 leading zeroes
+ * 5. The number of leading zeroes is subtracted from the maximum number of
+ * significant digits, 8, at 7 1/2 digits resolution.
+ * For a 10 V full resolution reading, this gives:
+ * : 10.000000 V, 0 leading zeroes => 8 significant digits
+ * : 9.999999 V, 1 leading zero => 7 significant digits
+ * : 0.999999 V, 2 leading zeroes => 6 significant digits
+ *
+ * Single precision floating point numbers can achieve about 16 million counts,
+ * but in high resolution mode we can get as much as 30 million counts. As a
+ * result, these calculations must be done with double precision
+ * (the HP 3457A is a very precise instrument).
+ */
+static int calculate_num_zero_digits(double measurement, double range)
+{
+ int zero_digits;
+ double min_full_res_reading, log10_range, full_res_ratio;
+
+ log10_range = log10(range);
+ min_full_res_reading = pow(10, (int)log10_range);
+ if (measurement > min_full_res_reading) {
+ zero_digits = 0;
+ } else if (measurement == 0.0) {
+ zero_digits = 0;
+ } else {
+ full_res_ratio = min_full_res_reading / measurement;
+ zero_digits = ceil(log10(ceil(full_res_ratio)));
+ }
+
+ return zero_digits;
+}
+
+/*
+ * Until the output modules understand double precision data, we need to send
+ * the measurement as floats instead of doubles, hence, the dance with
+ * measurement_workaround double to float conversion.
+ * See bug #779 for details.
+ * The workaround should be removed once the output modules are fixed.
+ */
+static void acq_send_measurement(struct sr_dev_inst *sdi)
+{
+ double hires_measurement;
+ float measurement_workaround;
+ int zero_digits, num_digits;
+ struct sr_datafeed_packet packet;
+ struct sr_datafeed_analog analog;
+ struct sr_analog_encoding encoding;
+ struct sr_analog_meaning meaning;
+ struct sr_analog_spec spec;
+ struct dev_context *devc = sdi->priv;
+
+ hires_measurement = devc->base_measurement;
+ if (is_highres_enabled(devc))
+ hires_measurement += devc->hires_register;
+
+ /* Figure out how many of the digits are significant. */
+ num_digits = is_highres_enabled(devc) ? 8 : 7;
+ zero_digits = calculate_num_zero_digits(hires_measurement,
+ devc->measurement_range);
+ num_digits = num_digits - zero_digits;
+
+ packet.type = SR_DF_ANALOG;
+ packet.payload = &analog;
+
+ sr_analog_init(&analog, &encoding, &meaning, &spec, num_digits);
+ encoding.unitsize = sizeof(float);
+
+ meaning.channels = g_slist_append(NULL, devc->current_channel);
+
+ measurement_workaround = hires_measurement;
+ analog.num_samples = 1;
+ analog.data = &measurement_workaround;
+
+ meaning.mq = devc->measurement_mq;
+ meaning.mqflags = devc->measurement_mq_flags;
+ meaning.unit = devc->measurement_unit;
+
+ sr_session_send(sdi, &packet);
+
+ g_slist_free(meaning.channels);
+}
+
+/*
+ * The scan-advance channel sync -- call to request_current_channel() -- is not
+ * necessarily needed. It is done in case we have a communication error and the
+ * DMM advances the channel without having sent the reading. The DMM only
+ * advances the channel when it thinks it sent the reading over HP-IB. Thus, on
+ * most errors we can retrigger the measurement and still be in sync. This
+ * check is done to make sure we don't fall out of sync due to obscure errors.
+ */
SR_PRIV int hp_3457a_receive_data(int fd, int revents, void *cb_data)
{
- const struct sr_dev_inst *sdi;
+ int ret;
+ struct sr_scpi_dev_inst *scpi;
struct dev_context *devc;
+ struct channel_context *chanc;
+ struct sr_dev_inst *sdi;
(void)fd;
+ (void)revents;
if (!(sdi = cb_data))
return TRUE;
if (!(devc = sdi->priv))
return TRUE;
- if (revents == G_IO_IN) {
- /* TODO */
+ scpi = sdi->conn;
+
+ switch (devc->acq_state) {
+ case ACQ_TRIGGERED_MEASUREMENT:
+ ret = sr_scpi_get_double(scpi, NULL, &devc->base_measurement);
+ if (ret != SR_OK) {
+ retrigger_measurement(scpi, devc);
+ return TRUE;
+ }
+
+ if (is_highres_enabled(devc))
+ request_hires(scpi, devc);
+ else
+ request_range(scpi, devc);
+
+ break;
+ case ACQ_REQUESTED_HIRES:
+ ret = sr_scpi_get_double(scpi, NULL, &devc->hires_register);
+ if (ret != SR_OK) {
+ retrigger_measurement(scpi, devc);
+ return TRUE;
+ }
+ request_range(scpi, devc);
+ break;
+ case ACQ_REQUESTED_RANGE:
+ ret = sr_scpi_get_double(scpi, NULL, &devc->measurement_range);
+ if (ret != SR_OK) {
+ retrigger_measurement(scpi, devc);
+ return TRUE;
+ }
+ devc->acq_state = ACQ_GOT_MEASUREMENT;
+ break;
+ case ACQ_REQUESTED_CHANNEL_SYNC:
+ ret = sr_scpi_get_double(scpi, NULL, &devc->last_channel_sync);
+ if (ret != SR_OK) {
+ sr_err("Cannot check channel synchronization.");
+ sr_dev_acquisition_stop(sdi);
+ return FALSE;
+ }
+ devc->acq_state = ACQ_GOT_CHANNEL_SYNC;
+ break;
+ default:
+ return FALSE;
+ }
+
+ if (devc->acq_state == ACQ_GOT_MEASUREMENT) {
+ acq_send_measurement(sdi);
+ devc->num_samples++;
+ }
+
+ if (devc->acq_state == ACQ_GOT_CHANNEL_SYNC) {
+ chanc = devc->current_channel->priv;
+ if (chanc->index != devc->last_channel_sync) {
+ sr_err("Current channel and scan advance out of sync.");
+ sr_err("Expected channel %u, but device says %u",
+ chanc->index,
+ (unsigned int)devc->last_channel_sync);
+ sr_dev_acquisition_stop(sdi);
+ return FALSE;
+ }
+ /* All is good. Back to business. */
+ retrigger_measurement(scpi, devc);
+ }
+
+ if (devc->limit_samples && (devc->num_samples >= devc->limit_samples)) {
+ sr_dev_acquisition_stop(sdi);
+ return FALSE;
+ }
+
+ /* Got more to go. */
+ if (devc->acq_state == ACQ_GOT_MEASUREMENT) {
+ activate_next_channel(devc);
+ /* Retrigger, or check if scan-advance is in sync. */
+ if (((devc->num_samples % 10) == 9)
+ && (devc->num_active_channels > 1)) {
+ request_current_channel(scpi, devc);
+ } else {
+ retrigger_measurement(scpi, devc);
+ }
}
return TRUE;
projects / libsigrok.git / blobdiff