Sensoray 7429 User Manual
Page 27
Tare Gage
This command tares the strain/pressure gage connected to the specified channel. Gage
taring is commonly used to subtract off the load offset created by the weight of an un-
loaded container. Offsets can also be caused by an imbalance in the gage bridge circuit.
Note that the tare gage command adjusts gage offset only and has no influence over
gain (sometimes called "span"). Gage span may be altered by modifying the gage pa-
rameters specifed as part of the define channel sensor command.
After executing this command, all sensor data from the specified channel (accessed via
the read channel data command) will be adjusted to compensate for the offset. Data
following the first command byte is set to the current desired output value of the gage
channel.
COMMAND:
(112 + CHAN),(MSB DATA),(LSB DATA)
RESPONSE:
NONE
Example: Channel 3 has been previously configured for a strain gage via the define
channel sensor command. When configured as such, data scaling was established
at 20 psi/bit. This particular gage exhibits a 60 psi offset at zero load, so it is nec-
essary to correct for bridge imbalance when taring a load.
This code segment will tare the current gage load:
gageScalar% = 20
gageOffset% = 60 / gageScalar%
tareWeight% = 0 / gageScalar%
CALL SendByte (112 + 3)'opcode + chan
CALL SendWord (tareWeight% - gageOffset)'desired data value