static int parse_range_vdc(struct dev_context *devc, uint8_t range_byte)
{
- if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30MV) {
+ if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30MV)
devc->enc_digits = devc->spec_digits - 2;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300MV) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300MV)
devc->enc_digits = devc->spec_digits - 3;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_3V) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_3V)
devc->enc_digits = devc->spec_digits - 1;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30V) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30V)
devc->enc_digits = devc->spec_digits - 2;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300V) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300V)
devc->enc_digits = devc->spec_digits - 3;
- } else {
+ else
return SR_ERR_DATA;
- }
return SR_OK;
}
static int parse_range_vac(struct dev_context *devc, uint8_t range_byte)
{
- if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300MV) {
+ if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300MV)
devc->enc_digits = devc->spec_digits - 3;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_3V) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_3V)
devc->enc_digits = devc->spec_digits - 1;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_30V) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_30V)
devc->enc_digits = devc->spec_digits - 2;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300V) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300V)
devc->enc_digits = devc->spec_digits - 3;
- } else {
+ else
return SR_ERR_DATA;
- }
return SR_OK;
}
static int parse_range_a(struct dev_context *devc, uint8_t range_byte)
{
- if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_300MA) {
+ if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_300MA)
devc->enc_digits = devc->spec_digits - 3;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_3A) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_3A)
devc->enc_digits = devc->spec_digits - 1;
- } else {
+ else
return SR_ERR_DATA;
- }
return SR_OK;
}
static int parse_range_ohm(struct dev_context *devc, uint8_t range_byte)
{
- if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30R) {
+ if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30R)
devc->enc_digits = devc->spec_digits - 2;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300R) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300R)
devc->enc_digits = devc->spec_digits - 3;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3KR) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3KR)
devc->enc_digits = devc->spec_digits - 1;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30KR) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30KR)
devc->enc_digits = devc->spec_digits - 2;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300KR) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300KR)
devc->enc_digits = devc->spec_digits - 3;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3MR) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3MR)
devc->enc_digits = devc->spec_digits - 1;
- } else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30MR) {
+ else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30MR)
devc->enc_digits = devc->spec_digits - 2;
- } else {
+ else
return SR_ERR_DATA;
- }
return SR_OK;
}
static int parse_function_byte(struct dev_context *devc, uint8_t function_byte)
{
- devc->measurement_mq_flags = 0;
+ /* Digits / Resolution (spec_digits must be set before range parsing) */
+ if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_5_5)
+ devc->spec_digits = 6;
+ else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_4_5)
+ devc->spec_digits = 5;
+ else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_3_5)
+ devc->spec_digits = 4;
+ else
+ return SR_ERR_DATA;
/* Function + Range */
+ devc->measurement_mq_flags = 0;
if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_VDC) {
devc->measurement_mq = SR_MQ_VOLTAGE;
devc->measurement_mq_flags |= SR_MQFLAG_DC;
parse_range_ohm(devc, function_byte);
}
- /* Digits / Resolution */
- if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_5_5) {
- devc->spec_digits = 5;
- } else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_4_5) {
- devc->spec_digits = 4;
- } else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_3_5) {
- devc->spec_digits = 3;
- }
-
return SR_OK;
}
struct sr_scpi_dev_inst *scpi;
struct sr_dev_inst *sdi;
struct dev_context *devc;
+ char status_register;
(void)fd;
(void)revents;
scpi = sdi->conn;
/*
- * This is necessary to get the actual range for the encoding digits.
- * When SPoll is implemmented, this can be done via SPoll.
+ * TODO: Wait for SRQ from the DMM when a new measurement is available.
+ * For now, we don't wait for a SRQ, but just do a SPoll and
+ * check the Data Ready bit (0x01).
+ * This is necessary, because (1) reading a value will block the
+ * bus until a measurement is available and (2) when switching
+ * ranges, there could be a timeout.
*/
- if (hp_3478a_get_status_bytes(sdi) != SR_OK)
+ if (sr_scpi_gpib_spoll(scpi, &status_register) != SR_OK)
+ return FALSE;
+ if (!(((uint8_t)status_register) & 0x01))
+ return TRUE;
+
+ /* Get a reading from the DMM. */
+ if (sr_scpi_get_double(scpi, NULL, &devc->measurement) != SR_OK)
return FALSE;
/*
- * TODO: Implement GPIB-SPoll, to get notified by a SRQ when a new
- * measurement is available. This is necessary, because when
- * switching ranges, there could be a timeout.
+ * This is necessary to get the actual range for the encoding digits.
+ * Must be called after reading the value, because it resets the
+ * status register!
*/
- if (sr_scpi_get_double(scpi, NULL, &devc->measurement) != SR_OK)
+ if (hp_3478a_get_status_bytes(sdi) != SR_OK)
return FALSE;
acq_send_measurement(sdi);