VTI Instruments EX1629, User Manual

Page: 186 / 346

VTI Instruments Corp.
186 EX1629 Command Set
vtex1629_get_shunt_value
F
UNCTION
P
ROTOTYPE
ViStatus vtex1629_get_shunt_value (ViSession vi , ViInt32 channel , ViInt32 shuntSource , ViPReal64
shuntValue );
F
UNCTION
P
ARAMETERS
vi = contains a session handle to the instrument. This handle is obtained by the function and remains valid until the
session is closed.
channel = an integer input value that specifies the channel for which the shunt value will be returned. Valid input
values: 0 to 47.
shuntSource = an integer input value indicating the source of the desired shunt value. Valid input values: 0 to 4.
shuntValue = a real return value indicating the shunt value for the given channel and shunt source.
D
ATA
I
TEM
R
ESET
V
ALUE
Not applicable to this function.
D
ESCRIPTION
This function queries and returns a shunt resistor value based on a given channel and shunt source. The
shuntSource parameter returns an integer value, 0 through 4, which correlates to the following shunt sources:
Decimal
Value
Hex
Value
#define Symbol shuntSource Description
0 0x00 VTEX1629_FRONT_PANEL_REMOTE Front panel remote
1 0x01 VTEX1629_FRONT_PANEL_LOCAL Front panel local
2 0x02 VTEX1629_INTERNAL_REMOTE Internal remote
3 0x03 VTEX1629_INTERNAL_REMOTE Internal local
4 0x04 VTEX1629_TEDS_REMOTE TEDS remote
Local and Remote refer to how the shunt resistor is connected to the bridge. For “Local”, the connection is made
within the EX1629. For “Remote”, the connection is made externally, using the ±RCal signals.
Front Panel, Internal, and TEDS, refer to the three types of shunt sources supported. “Front Panel” refers to the
shunt resistors that may be connected directly to the front panel of the EX1629, which are shared by 16 channels
(0 through 15, 16 through 31, and 32 through 47). Only one channel may be connected to the Front Panel shunt at a
time. “Internal” refers to the internal, per-channel shunt resistor. Since each channel has its own, all channels may be
shunted simultaneously. “TEDS” refers to a special shunt resistor/TEDS (1-Wire) configuration. Only one channel
may be shunted via the TEDS shunt at a time.
Any shunt source mode may be queried for its value, regardless of whether it is selected as the current mode or
enabled.
E
XAMPLE
ViSession instrumentHandle;
ViStatus status;
ViInt32 shunt_src;
ViReal64 shunt_value;
…
status = vtex1629_get_shunt_value(instrumentHandle, 0, &shunt_src, &shunt_value);