scpi-dmm: Added minimal support for HP34401A (PR #36)

[libsigrok.git] / src / hardware / scpi-dmm / protocol.c

diff --git a/src/hardware/scpi-dmm/protocol.c b/src/hardware/scpi-dmm/protocol.c
index 08c79b4a19be39bcffaf619b5e10c8c2e8ed5dbf..d0cafd829f05d82463e1a91b8f388f65e76b3af8 100644 (file)
--- a/src/hardware/scpi-dmm/protocol.c
+++ b/src/hardware/scpi-dmm/protocol.c
@@ -70,7 +70,8 @@ SR_PRIV const struct mqopt_item *scpi_dmm_lookup_mq_text(
 }
 
 SR_PRIV int scpi_dmm_get_mq(const struct sr_dev_inst *sdi,
-       enum sr_mq *mq, enum sr_mqflag *flag, char **rsp)
+       enum sr_mq *mq, enum sr_mqflag *flag, char **rsp,
+       const struct mqopt_item **mqitem)
 {
        struct dev_context *devc;
        const char *command;
@@ -86,13 +87,15 @@ SR_PRIV int scpi_dmm_get_mq(const struct sr_dev_inst *sdi,
                *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);
-       scpi_dmm_cmd_delay(sdi->conn);
        if (ret != SR_OK)
                return ret;
        if (!response || !*response)
@@ -108,6 +111,8 @@ SR_PRIV int scpi_dmm_get_mq(const struct sr_dev_inst *sdi,
                        *mq = item->mq;
                if (flag)
                        *flag = item->mqflag;
+               if (mqitem)
+                       *mqitem = item;
                ret = SR_OK;
        }
 
@@ -135,10 +140,12 @@ SR_PRIV int scpi_dmm_set_mq(const struct sr_dev_inst *sdi,
 
        mode = item->scpi_func_setup;
        command = sr_scpi_cmd_get(devc->cmdset, DMM_CMD_SETUP_FUNC);
-       ret = sr_scpi_send(sdi->conn, command, mode);
        scpi_dmm_cmd_delay(sdi->conn);
+       ret = sr_scpi_send(sdi->conn, command, mode);
+       if (ret != SR_OK)
+               return ret;
 
-       return ret;
+       return SR_OK;
 }
 
 SR_PRIV int scpi_dmm_get_meas_agilent(const struct sr_dev_inst *sdi, size_t ch)
@@ -173,7 +180,7 @@ SR_PRIV int scpi_dmm_get_meas_agilent(const struct sr_dev_inst *sdi, size_t 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);
+       ret = scpi_dmm_get_mq(sdi, &mq, &mqflag, &mode_response, &item);
        if (ret != SR_OK) {
                g_free(mode_response);
                return ret;
@@ -200,17 +207,14 @@ SR_PRIV int scpi_dmm_get_meas_agilent(const struct sr_dev_inst *sdi, size_t ch)
                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 {
-               item = scpi_dmm_lookup_mq_number(sdi, mq, mqflag);
-               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;
-               }
+               snprintf(prec_text, sizeof(prec_text),
+                       "1e%d", item->default_precision);
+               p = prec_text;
        }
        g_strfreev(fields);
 
@@ -265,8 +269,8 @@ SR_PRIV int scpi_dmm_get_meas_agilent(const struct sr_dev_inst *sdi, size_t ch)
        command = sr_scpi_cmd_get(devc->cmdset, DMM_CMD_QUERY_VALUE);
        if (!command || !*command)
                return SR_ERR_NA;
-       ret = sr_scpi_get_string(scpi, command, &response);
        scpi_dmm_cmd_delay(scpi);
+       ret = sr_scpi_get_string(scpi, command, &response);
        if (ret != SR_OK)
                return ret;
        g_strstrip(response);
@@ -382,6 +386,9 @@ SR_PRIV int scpi_dmm_get_meas_agilent(const struct sr_dev_inst *sdi, size_t ch)
        case SR_MQ_FREQUENCY:
                unit = SR_UNIT_HERTZ;
                break;
+       case SR_MQ_TIME:
+               unit = SR_UNIT_SECOND;
+               break;
        default:
                return SR_ERR_NA;
        }