VTI Instruments Corp.
128
EX1629 Command Set
vtex1629_get_bridge_limit
F
UNCTION
P
ROTOTYPE
ViStatus vtex1629_get_bridge_limit (ViSession
vi
, ViInt32
channel
, ViPReal64
min
, ViPReal64
max
);
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 indicating the channel for which the completion resistor is desired. Valid input
values: 0 to 47.
min
= the returned minimum bridge limit value.
max
= the returned minimum bridge limit value.
D
ATA
I
TEM
R
ESET
V
ALUE
Not applicable to this function.
D
ESCRIPTION
This function queries and returns the minimum and maximum bridge limit values. The limit check data is part of the
data page along with the bridge data. If the bridge data exceeds the maximum or minimum limit values set for any
channel, the corresponding flags are set in the limit check result field in a data page.
0 = Bridge data is
less than the MAX
for CH 15
1 = Bridge data is
greater than the
MAX for CH 15
0 = Bridge data is
less than the MAX
for CH 0
1 = Bridge data is
greater than the
MAX for CH 0
0 = Bridge data is
greater than the
MIN for CH 15
1 = Bridge data is
less than the MIN
for CH 15
0 = Bridge data is
greater than the
MIN for CH 0
1 = Bridge data is
less than the MIN
for CH 0
31
0
15
MSW
(MAX Limit exceeded status)
LSW
(MIN Limit exceeded status)
The “limits” field is a bit-field. This UINT32 has two bits per channel (16-channels per analog board), one to
represent MAX limit exceeded and one to represent MIN limit exceeded. The MSW (upper 16-bits) represent the
MAX Limit Exceeded status for each of the 16-channels, and the LSW (lower 16-bits) represent the MIN Limit
Exceeded status for each of the 16-channels. Bit 0 represents the MIN Limit Exceeded status for channel 0 (channels
0, 16, 32). Bit 16 represents the MAX Limit Exceeded status for Channel 0 (channels 0, 16, 32). Bit 15 represents
the MIN Limit Exceeded status for channel 15 (channels 15, 31, and 47). Bit 31 represents the MAX Limit
Exceeded status for channel 15 (channels 15, 31, and 47). The rest of the channels follow the same pattern.
NOTE
The channel-to-bit mapping is constant, regardless of scanlist configuration. For example, whether
or not channels 0 and 1 are enabled in the scanlist, for instance, channel 2’s MIN Limit Exceeded
Bit and MAX Limit Exceeded Bit are always bits 2 and 18, respectively.
This mode is valid for main bridge sampling frequencies of 1 kHz or less. If the sampling frequency exceeds 1 kHz
a value of 0x0 is reported. Also, the bit fields corresponding to inactive channels in the scanlist will be 0.
Limit checking is performed on the output of the EU conversion. So, if the specified EU conversion is in Strain
(quarter-, half-, or full-bridge) the limit values are in strain (or microstrain). If the specified EU conversion is volts,
then the limit values are in volts.
