]> sigrok.org Git - libsigrok.git/blobdiff - src/hardware/hameg-hmo/protocol.c
hameg-hmo: Add SR_CONF_LIMIT_SAMPLES support.
[libsigrok.git] / src / hardware / hameg-hmo / protocol.c
index 12e79c47393ec342cd0719fa8634cfd6aea3f911..41b14d48b71aa5b10fe01cec522b23a5ae6c5333 100644 (file)
@@ -57,8 +57,9 @@ static const char *hameg_scpi_dialect[] = {
        [SCPI_CMD_GET_PROBE_UNIT]           = ":PROB%d:SET:ATT:UNIT?",
 };
 
-static const uint32_t hmo_devopts[] = {
+static const uint32_t devopts[] = {
        SR_CONF_OSCILLOSCOPE,
+       SR_CONF_LIMIT_SAMPLES | SR_CONF_GET | SR_CONF_SET,
        SR_CONF_LIMIT_FRAMES | SR_CONF_GET | SR_CONF_SET,
        SR_CONF_SAMPLERATE | SR_CONF_GET,
        SR_CONF_TIMEBASE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
@@ -68,98 +69,57 @@ static const uint32_t hmo_devopts[] = {
        SR_CONF_TRIGGER_SLOPE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
 };
 
-static const uint32_t hmo_analog_devopts[] = {
+static const uint32_t devopts_cg_analog[] = {
        SR_CONF_NUM_VDIV | SR_CONF_GET,
        SR_CONF_VDIV | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
        SR_CONF_COUPLING | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
 };
 
-static const char *hmo_coupling_options[] = {
+static const char *coupling_options[] = {
        "AC",  // AC with 50 Ohm termination (152x, 202x, 30xx, 1202)
        "ACL", // AC with 1 MOhm termination
        "DC",  // DC with 50 Ohm termination
        "DCL", // DC with 1 MOhm termination
        "GND",
-       NULL,
 };
 
 static const char *scope_trigger_slopes[] = {
        "POS",
        "NEG",
        "EITH",
-       NULL,
 };
 
-static const char *hmo_compact2_trigger_sources[] = {
-       "CH1",
-       "CH2",
-       "LINE",
-       "EXT",
-       "PATT",
-       "BUS1",
-       "BUS2",
-       "D0",
-       "D1",
-       "D2",
-       "D3",
-       "D4",
-       "D5",
-       "D6",
-       "D7",
-       NULL,
+/* HMO compact2 */
+static const char *an2_dig8_trigger_sources[] = {
+       "CH1", "CH2",
+       "LINE", "EXT", "PATT", "BUS1", "BUS2",
+       "D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
 };
 
-static const char *hmo_compact4_trigger_sources[] = {
-       "CH1",
-       "CH2",
-       "CH3",
-       "CH4",
-       "LINE",
-       "EXT",
-       "PATT",
-       "BUS1",
-       "BUS2",
-       "D0",
-       "D1",
-       "D2",
-       "D3",
-       "D4",
-       "D5",
-       "D6",
-       "D7",
-       NULL,
+/* HMO xxx2 */
+static const char *an2_dig16_trigger_sources[] = {
+       "CH1", "CH2",
+       "LINE", "EXT", "PATT", "BUS1", "BUS2",
+       "D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
+       "D8", "D9", "D10", "D11", "D12", "D13", "D14", "D15",
 };
 
-static const char *hmo_compact4_dig16_trigger_sources[] = {
-       "CH1",
-       "CH2",
-       "CH3",
-       "CH4",
-       "LINE",
-       "EXT",
-       "PATT",
-       "BUS1",
-       "BUS2",
-       "D0",
-       "D1",
-       "D2",
-       "D3",
-       "D4",
-       "D5",
-       "D6",
-       "D7",
-       "D8",
-       "D9",
-       "D10",
-       "D11",
-       "D12",
-       "D13",
-       "D14",
-       "D15",
-       NULL,
+/* HMO compact4 */
+static const char *an4_dig8_trigger_sources[] = {
+       "CH1", "CH2", "CH3", "CH4",
+       "LINE", "EXT", "PATT", "BUS1", "BUS2",
+       "D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
 };
 
-static const uint64_t hmo_timebases[][2] = {
+/* HMO xxx4 */
+static const char *an4_dig16_trigger_sources[] = {
+       "CH1", "CH2", "CH3", "CH4",
+       "LINE", "EXT", "PATT", "BUS1", "BUS2",
+       "D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
+       "D8", "D9", "D10", "D11", "D12", "D13", "D14", "D15",
+};
+
+static const uint64_t timebases[][2] = {
        /* nanoseconds */
        { 2, 1000000000 },
        { 5, 1000000000 },
@@ -198,7 +158,7 @@ static const uint64_t hmo_timebases[][2] = {
        { 50, 1 },
 };
 
-static const uint64_t hmo_vdivs[][2] = {
+static const uint64_t vdivs[][2] = {
        /* millivolts */
        { 1, 1000 },
        { 2, 1000 },
@@ -219,36 +179,18 @@ static const uint64_t hmo_vdivs[][2] = {
 };
 
 static const char *scope_analog_channel_names[] = {
-       "CH1",
-       "CH2",
-       "CH3",
-       "CH4",
+       "CH1", "CH2", "CH3", "CH4",
 };
 
 static const char *scope_digital_channel_names[] = {
-       "D0",
-       "D1",
-       "D2",
-       "D3",
-       "D4",
-       "D5",
-       "D6",
-       "D7",
-       "D8",
-       "D9",
-       "D10",
-       "D11",
-       "D12",
-       "D13",
-       "D14",
-       "D15",
+       "D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7",
+       "D8", "D9", "D10", "D11", "D12", "D13", "D14", "D15",
 };
 
 static const struct scope_config scope_models[] = {
        {
-               /* HMO2522/3032/3042/3052 support 16 digital channels but they're not supported yet. */
-               .name = {"HMO1002", "HMO722", "HMO1022", "HMO1522", "HMO2022", "HMO2522",
-                               "HMO3032", "HMO3042", "HMO3052", NULL},
+               /* HMO722/1002/1022/1522/2022 support only 8 digital channels. */
+               .name = {"HMO722", "HMO1002", "HMO1022", "HMO1522", "HMO2022", NULL},
                .analog_channels = 2,
                .digital_channels = 8,
                .digital_pods = 1,
@@ -256,21 +198,62 @@ static const struct scope_config scope_models[] = {
                .analog_names = &scope_analog_channel_names,
                .digital_names = &scope_digital_channel_names,
 
-               .devopts = &hmo_devopts,
-               .num_devopts = ARRAY_SIZE(hmo_devopts),
+               .devopts = &devopts,
+               .num_devopts = ARRAY_SIZE(devopts),
+
+               .devopts_cg_analog = &devopts_cg_analog,
+               .num_devopts_cg_analog = ARRAY_SIZE(devopts_cg_analog),
 
-               .analog_devopts = &hmo_analog_devopts,
-               .num_analog_devopts = ARRAY_SIZE(hmo_analog_devopts),
+               .coupling_options = &coupling_options,
+               .num_coupling_options = ARRAY_SIZE(coupling_options),
+
+               .trigger_sources = &an2_dig8_trigger_sources,
+               .num_trigger_sources = ARRAY_SIZE(an2_dig8_trigger_sources),
 
-               .coupling_options = &hmo_coupling_options,
-               .trigger_sources = &hmo_compact2_trigger_sources,
                .trigger_slopes = &scope_trigger_slopes,
+               .num_trigger_slopes = ARRAY_SIZE(scope_trigger_slopes),
 
-               .timebases = &hmo_timebases,
-               .num_timebases = ARRAY_SIZE(hmo_timebases),
+               .timebases = &timebases,
+               .num_timebases = ARRAY_SIZE(timebases),
 
-               .vdivs = &hmo_vdivs,
-               .num_vdivs = ARRAY_SIZE(hmo_vdivs),
+               .vdivs = &vdivs,
+               .num_vdivs = ARRAY_SIZE(vdivs),
+
+               .num_xdivs = 12,
+               .num_ydivs = 8,
+
+               .scpi_dialect = &hameg_scpi_dialect,
+       },
+       {
+               /* HMO3032/3042/3052/3522 support 16 digital channels. */
+               .name = {"HMO3032", "HMO3042", "HMO3052", "HMO3522", NULL},
+               .analog_channels = 2,
+               .digital_channels = 16,
+               .digital_pods = 2,
+
+               .analog_names = &scope_analog_channel_names,
+               .digital_names = &scope_digital_channel_names,
+
+               .devopts = &devopts,
+               .num_devopts = ARRAY_SIZE(devopts),
+
+               .devopts_cg_analog = &devopts_cg_analog,
+               .num_devopts_cg_analog = ARRAY_SIZE(devopts_cg_analog),
+
+               .coupling_options = &coupling_options,
+               .num_coupling_options = ARRAY_SIZE(coupling_options),
+
+               .trigger_sources = &an2_dig16_trigger_sources,
+               .num_trigger_sources = ARRAY_SIZE(an2_dig16_trigger_sources),
+
+               .trigger_slopes = &scope_trigger_slopes,
+               .num_trigger_slopes = ARRAY_SIZE(scope_trigger_slopes),
+
+               .timebases = &timebases,
+               .num_timebases = ARRAY_SIZE(timebases),
+
+               .vdivs = &vdivs,
+               .num_vdivs = ARRAY_SIZE(vdivs),
 
                .num_xdivs = 12,
                .num_ydivs = 8,
@@ -286,21 +269,26 @@ static const struct scope_config scope_models[] = {
                .analog_names = &scope_analog_channel_names,
                .digital_names = &scope_digital_channel_names,
 
-               .devopts = &hmo_devopts,
-               .num_devopts = ARRAY_SIZE(hmo_devopts),
+               .devopts = &devopts,
+               .num_devopts = ARRAY_SIZE(devopts),
+
+               .devopts_cg_analog = &devopts_cg_analog,
+               .num_devopts_cg_analog = ARRAY_SIZE(devopts_cg_analog),
 
-               .analog_devopts = &hmo_analog_devopts,
-               .num_analog_devopts = ARRAY_SIZE(hmo_analog_devopts),
+               .coupling_options = &coupling_options,
+               .num_coupling_options = ARRAY_SIZE(coupling_options),
+
+               .trigger_sources = &an4_dig8_trigger_sources,
+               .num_trigger_sources = ARRAY_SIZE(an4_dig8_trigger_sources),
 
-               .coupling_options = &hmo_coupling_options,
-               .trigger_sources = &hmo_compact4_trigger_sources,
                .trigger_slopes = &scope_trigger_slopes,
+               .num_trigger_slopes = ARRAY_SIZE(scope_trigger_slopes),
 
-               .timebases = &hmo_timebases,
-               .num_timebases = ARRAY_SIZE(hmo_timebases),
+               .timebases = &timebases,
+               .num_timebases = ARRAY_SIZE(timebases),
 
-               .vdivs = &hmo_vdivs,
-               .num_vdivs = ARRAY_SIZE(hmo_vdivs),
+               .vdivs = &vdivs,
+               .num_vdivs = ARRAY_SIZE(vdivs),
 
                .num_xdivs = 12,
                .num_ydivs = 8,
@@ -316,21 +304,26 @@ static const struct scope_config scope_models[] = {
                .analog_names = &scope_analog_channel_names,
                .digital_names = &scope_digital_channel_names,
 
-               .devopts = &hmo_devopts,
-               .num_devopts = ARRAY_SIZE(hmo_devopts),
+               .devopts = &devopts,
+               .num_devopts = ARRAY_SIZE(devopts),
+
+               .devopts_cg_analog = &devopts_cg_analog,
+               .num_devopts_cg_analog = ARRAY_SIZE(devopts_cg_analog),
 
-               .analog_devopts = &hmo_analog_devopts,
-               .num_analog_devopts = ARRAY_SIZE(hmo_analog_devopts),
+               .coupling_options = &coupling_options,
+               .num_coupling_options = ARRAY_SIZE(coupling_options),
+
+               .trigger_sources = &an4_dig16_trigger_sources,
+               .num_trigger_sources = ARRAY_SIZE(an4_dig16_trigger_sources),
 
-               .coupling_options = &hmo_coupling_options,
-               .trigger_sources = &hmo_compact4_dig16_trigger_sources,
                .trigger_slopes = &scope_trigger_slopes,
+               .num_trigger_slopes = ARRAY_SIZE(scope_trigger_slopes),
 
-               .timebases = &hmo_timebases,
-               .num_timebases = ARRAY_SIZE(hmo_timebases),
+               .timebases = &timebases,
+               .num_timebases = ARRAY_SIZE(timebases),
 
-               .vdivs = &hmo_vdivs,
-               .num_vdivs = ARRAY_SIZE(hmo_vdivs),
+               .vdivs = &vdivs,
+               .num_vdivs = ARRAY_SIZE(vdivs),
 
                .num_xdivs = 12,
                .num_ydivs = 8,
@@ -380,30 +373,25 @@ static void scope_state_dump(const struct scope_config *config,
 }
 
 static int scope_state_get_array_option(struct sr_scpi_dev_inst *scpi,
-               const char *command, const char *(*array)[], int *result)
+               const char *command, const char *(*array)[], unsigned int n, int *result)
 {
        char *tmp;
-       unsigned int i;
+       int idx;
 
        if (sr_scpi_get_string(scpi, command, &tmp) != SR_OK) {
                g_free(tmp);
                return SR_ERR;
        }
 
-       for (i = 0; (*array)[i]; i++) {
-               if (!g_strcmp0(tmp, (*array)[i])) {
-                       *result = i;
-                       g_free(tmp);
-                       tmp = NULL;
-                       break;
-               }
-       }
-
-       if (tmp) {
+       if ((idx = std_str_idx_s(tmp, *array, n)) < 0) {
                g_free(tmp);
-               return SR_ERR;
+               return SR_ERR_ARG;
        }
 
+       *result = idx;
+
+       g_free(tmp);
+
        return SR_OK;
 }
 
@@ -438,13 +426,29 @@ static int array_float_get(gchar *value, const uint64_t array[][2],
        return SR_ERR;
 }
 
-static int analog_channel_state_get(struct sr_scpi_dev_inst *scpi,
+static struct sr_channel *get_channel_by_index_and_type(GSList *channel_lhead,
+                                                       int index, int type)
+{
+       while (channel_lhead) {
+               struct sr_channel *ch = channel_lhead->data;
+               if (ch->index == index && ch->type == type)
+                       return ch;
+
+               channel_lhead = channel_lhead->next;
+       }
+
+       return 0;
+}
+
+static int analog_channel_state_get(struct sr_dev_inst *sdi,
                                    const struct scope_config *config,
                                    struct scope_state *state)
 {
        unsigned int i, j;
        char command[MAX_COMMAND_SIZE];
        char *tmp_str;
+       struct sr_channel *ch;
+       struct sr_scpi_dev_inst *scpi = sdi->conn;
 
        for (i = 0; i < config->analog_channels; i++) {
                g_snprintf(command, sizeof(command),
@@ -455,6 +459,10 @@ static int analog_channel_state_get(struct sr_scpi_dev_inst *scpi,
                                     &state->analog_channels[i].state) != SR_OK)
                        return SR_ERR;
 
+               ch = get_channel_by_index_and_type(sdi->channels, i, SR_CHANNEL_ANALOG);
+               if (ch)
+                       ch->enabled = state->analog_channels[i].state;
+
                g_snprintf(command, sizeof(command),
                           (*config->scpi_dialect)[SCPI_CMD_GET_VERTICAL_DIV],
                           i + 1);
@@ -462,8 +470,7 @@ static int analog_channel_state_get(struct sr_scpi_dev_inst *scpi,
                if (sr_scpi_get_string(scpi, command, &tmp_str) != SR_OK)
                        return SR_ERR;
 
-               if (array_float_get(tmp_str, hmo_vdivs, ARRAY_SIZE(hmo_vdivs),
-                               &j) != SR_OK) {
+               if (array_float_get(tmp_str, ARRAY_AND_SIZE(vdivs), &j) != SR_OK) {
                        g_free(tmp_str);
                        sr_err("Could not determine array index for vertical div scale.");
                        return SR_ERR;
@@ -485,6 +492,7 @@ static int analog_channel_state_get(struct sr_scpi_dev_inst *scpi,
                           i + 1);
 
                if (scope_state_get_array_option(scpi, command, config->coupling_options,
+                                        config->num_coupling_options,
                                         &state->analog_channels[i].coupling) != SR_OK)
                        return SR_ERR;
 
@@ -505,12 +513,14 @@ static int analog_channel_state_get(struct sr_scpi_dev_inst *scpi,
        return SR_OK;
 }
 
-static int digital_channel_state_get(struct sr_scpi_dev_inst *scpi,
+static int digital_channel_state_get(struct sr_dev_inst *sdi,
                                     const struct scope_config *config,
                                     struct scope_state *state)
 {
        unsigned int i;
        char command[MAX_COMMAND_SIZE];
+       struct sr_channel *ch;
+       struct sr_scpi_dev_inst *scpi = sdi->conn;
 
        for (i = 0; i < config->digital_channels; i++) {
                g_snprintf(command, sizeof(command),
@@ -520,6 +530,10 @@ static int digital_channel_state_get(struct sr_scpi_dev_inst *scpi,
                if (sr_scpi_get_bool(scpi, command,
                                     &state->digital_channels[i]) != SR_OK)
                        return SR_ERR;
+
+               ch = get_channel_by_index_and_type(sdi->channels, i, SR_CHANNEL_LOGIC);
+               if (ch)
+                       ch->enabled = state->digital_channels[i];
        }
 
        for (i = 0; i < config->digital_pods; i++) {
@@ -540,7 +554,6 @@ SR_PRIV int hmo_update_sample_rate(const struct sr_dev_inst *sdi)
        struct dev_context *devc;
        struct scope_state *state;
        const struct scope_config *config;
-
        int tmp;
        unsigned int i;
        float tmp_float;
@@ -554,8 +567,21 @@ SR_PRIV int hmo_update_sample_rate(const struct sr_dev_inst *sdi)
        channel_found = FALSE;
 
        for (i = 0; i < config->analog_channels; i++) {
-               if (state->analog_channels[i].state) {
-                       g_snprintf(chan_name, sizeof(chan_name), "CHAN%d", i + 1);
+               if (!state->analog_channels[i].state)
+                       continue;
+               g_snprintf(chan_name, sizeof(chan_name), "CHAN%d", i + 1);
+               g_snprintf(tmp_str, sizeof(tmp_str),
+                          (*config->scpi_dialect)[SCPI_CMD_GET_SAMPLE_RATE_LIVE],
+                          chan_name);
+               channel_found = TRUE;
+               break;
+       }
+
+       if (!channel_found) {
+               for (i = 0; i < config->digital_pods; i++) {
+                       if (!state->digital_pods[i])
+                               continue;
+                       g_snprintf(chan_name, sizeof(chan_name), "POD%d", i);
                        g_snprintf(tmp_str, sizeof(tmp_str),
                                   (*config->scpi_dialect)[SCPI_CMD_GET_SAMPLE_RATE_LIVE],
                                   chan_name);
@@ -564,19 +590,6 @@ SR_PRIV int hmo_update_sample_rate(const struct sr_dev_inst *sdi)
                }
        }
 
-       if (!channel_found) {
-               for (i = 0; i < config->digital_pods; i++) {
-                       if (state->digital_pods[i]) {
-                               g_snprintf(chan_name, sizeof(chan_name), "POD%d", i);
-                               g_snprintf(tmp_str, sizeof(tmp_str),
-                                          (*config->scpi_dialect)[SCPI_CMD_GET_SAMPLE_RATE_LIVE],
-                                          chan_name);
-                               channel_found = TRUE;
-                               break;
-                       }
-               }
-       }
-
        /* No channel is active, ask the instrument for the sample rate
         * in single shot mode */
        if (!channel_found) {
@@ -612,10 +625,10 @@ SR_PRIV int hmo_scope_state_get(struct sr_dev_inst *sdi)
 
        sr_info("Fetching scope state");
 
-       if (analog_channel_state_get(sdi->conn, config, state) != SR_OK)
+       if (analog_channel_state_get(sdi, config, state) != SR_OK)
                return SR_ERR;
 
-       if (digital_channel_state_get(sdi->conn, config, state) != SR_OK)
+       if (digital_channel_state_get(sdi, config, state) != SR_OK)
                return SR_ERR;
 
        if (sr_scpi_get_float(sdi->conn,
@@ -628,8 +641,7 @@ SR_PRIV int hmo_scope_state_get(struct sr_dev_inst *sdi)
                        &tmp_str) != SR_OK)
                return SR_ERR;
 
-       if (array_float_get(tmp_str, hmo_timebases, ARRAY_SIZE(hmo_timebases),
-                       &i) != SR_OK) {
+       if (array_float_get(tmp_str, ARRAY_AND_SIZE(timebases), &i) != SR_OK) {
                g_free(tmp_str);
                sr_err("Could not determine array index for time base.");
                return SR_ERR;
@@ -650,12 +662,14 @@ SR_PRIV int hmo_scope_state_get(struct sr_dev_inst *sdi)
 
        if (scope_state_get_array_option(sdi->conn,
                        (*config->scpi_dialect)[SCPI_CMD_GET_TRIGGER_SOURCE],
-                       config->trigger_sources, &state->trigger_source) != SR_OK)
+                       config->trigger_sources, config->num_trigger_sources,
+                       &state->trigger_source) != SR_OK)
                return SR_ERR;
 
        if (scope_state_get_array_option(sdi->conn,
-               (*config->scpi_dialect)[SCPI_CMD_GET_TRIGGER_SLOPE],
-               config->trigger_slopes, &state->trigger_slope) != SR_OK)
+                       (*config->scpi_dialect)[SCPI_CMD_GET_TRIGGER_SLOPE],
+                       config->trigger_slopes, config->num_trigger_slopes,
+                       &state->trigger_slope) != SR_OK)
                return SR_ERR;
 
        if (hmo_update_sample_rate(sdi) != SR_OK)
@@ -693,11 +707,11 @@ SR_PRIV void hmo_scope_state_free(struct scope_state *state)
 
 SR_PRIV int hmo_init_device(struct sr_dev_inst *sdi)
 {
-       char tmp[25];
        int model_index;
        unsigned int i, j, group;
        struct sr_channel *ch;
        struct dev_context *devc;
+       int ret;
 
        devc = sdi->priv;
        model_index = -1;
@@ -721,9 +735,13 @@ SR_PRIV int hmo_init_device(struct sr_dev_inst *sdi)
 
        devc->analog_groups = g_malloc0(sizeof(struct sr_channel_group*) *
                                        scope_models[model_index].analog_channels);
-
        devc->digital_groups = g_malloc0(sizeof(struct sr_channel_group*) *
                                         scope_models[model_index].digital_pods);
+       if (!devc->analog_groups || !devc->digital_groups) {
+               g_free(devc->analog_groups);
+               g_free(devc->digital_groups);
+               return SR_ERR_MALLOC;
+       }
 
        /* Add analog channels. */
        for (i = 0; i < scope_models[model_index].analog_channels; i++) {
@@ -741,15 +759,19 @@ SR_PRIV int hmo_init_device(struct sr_dev_inst *sdi)
        }
 
        /* Add digital channel groups. */
+       ret = SR_OK;
        for (i = 0; i < scope_models[model_index].digital_pods; i++) {
-               g_snprintf(tmp, 25, "POD%d", i);
-
                devc->digital_groups[i] = g_malloc0(sizeof(struct sr_channel_group));
-
-               devc->digital_groups[i]->name = g_strdup(tmp);
+               if (!devc->digital_groups[i]) {
+                       ret = SR_ERR_MALLOC;
+                       break;
+               }
+               devc->digital_groups[i]->name = g_strdup_printf("POD%d", i);
                sdi->channel_groups = g_slist_append(sdi->channel_groups,
                                   devc->digital_groups[i]);
        }
+       if (ret != SR_OK)
+               return ret;
 
        /* Add digital channels. */
        for (i = 0; i < scope_models[model_index].digital_channels; i++) {
@@ -762,6 +784,7 @@ SR_PRIV int hmo_init_device(struct sr_dev_inst *sdi)
        }
 
        devc->model_config = &scope_models[model_index];
+       devc->samples_limit = 0;
        devc->frame_limit = 0;
 
        if (!(devc->model_state = scope_state_new(devc->model_config)))
@@ -800,8 +823,6 @@ SR_PRIV void hmo_queue_logic_data(struct dev_context *devc,
        } else {
                store = devc->logic_data;
                size = store->len / devc->pod_count;
-               if (size != pod_data->len)
-                       return;
                if (group >= devc->pod_count)
                        return;
        }
@@ -817,6 +838,10 @@ SR_PRIV void hmo_queue_logic_data(struct dev_context *devc,
                *logic_data = pod_data->data[idx];
                logic_data += logic_step;
        }
+
+       /* Truncate acquisition if a smaller number of samples has been requested. */
+       if (devc->samples_limit > 0 && devc->logic_data->len > devc->samples_limit * devc->pod_count)
+               devc->logic_data->len = devc->samples_limit * devc->pod_count;
 }
 
 /* Submit data for all channels, after the individual groups got collected. */
@@ -906,7 +931,6 @@ SR_PRIV int hmo_receive_data(int fd, int revents, void *cb_data)
                if (sr_scpi_get_block(sdi->conn, NULL, &data) != SR_OK) {
                        if (data)
                                g_byte_array_free(data, TRUE);
-
                        return TRUE;
                }
 
@@ -914,6 +938,9 @@ SR_PRIV int hmo_receive_data(int fd, int revents, void *cb_data)
 
                analog.data = data->data;
                analog.num_samples = data->len / sizeof(float);
+               /* Truncate acquisition if a smaller number of samples has been requested. */
+               if (devc->samples_limit > 0 && analog.num_samples > devc->samples_limit)
+                       analog.num_samples = devc->samples_limit;
                analog.encoding = &encoding;
                analog.meaning = &meaning;
                analog.spec = &spec;
@@ -946,13 +973,15 @@ SR_PRIV int hmo_receive_data(int fd, int revents, void *cb_data)
                spec.spec_digits = 2;
                packet.payload = &analog;
                sr_session_send(sdi, &packet);
+               devc->num_samples = data->len / sizeof(float);
                g_slist_free(meaning.channels);
                g_byte_array_free(data, TRUE);
                data = NULL;
                break;
        case SR_CHANNEL_LOGIC:
                if (sr_scpi_get_block(sdi->conn, NULL, &data) != SR_OK) {
-                       g_free(data);
+                       if (data)
+                               g_byte_array_free(data, TRUE);
                        return TRUE;
                }
 
@@ -973,6 +1002,9 @@ SR_PRIV int hmo_receive_data(int fd, int revents, void *cb_data)
                        packet.type = SR_DF_LOGIC;
                        logic.data = data->data;
                        logic.length = data->len;
+                       /* Truncate acquisition if a smaller number of samples has been requested. */
+                       if (devc->samples_limit > 0 && logic.length > devc->samples_limit)
+                               logic.length = devc->samples_limit;
                        logic.unitsize = 1;
                        packet.payload = &logic;
                        sr_session_send(sdi, &packet);
@@ -981,6 +1013,7 @@ SR_PRIV int hmo_receive_data(int fd, int revents, void *cb_data)
                        hmo_queue_logic_data(devc, group, data);
                }
 
+               devc->num_samples = data->len / devc->pod_count;
                g_byte_array_free(data, TRUE);
                data = NULL;
                break;
@@ -1014,10 +1047,10 @@ SR_PRIV int hmo_receive_data(int fd, int revents, void *cb_data)
 
        /*
         * End of frame was reached. Stop acquisition after the specified
-        * number of frames, or continue reception by starting over at
-        * the first enabled channel.
+        * number of frames or after the specified number of samples, or
+        * continue reception by starting over at the first enabled channel.
         */
-       if (++devc->num_frames == devc->frame_limit) {
+       if (++devc->num_frames >= devc->frame_limit || devc->num_samples >= devc->samples_limit) {
                sr_dev_acquisition_stop(sdi);
                hmo_cleanup_logic_data(devc);
        } else {