Specifications

Command Set 4-18
Caution! TS is the only command associated with the span trim. There is no
provision to read back or clear errors loaded by the TS command. Misuse
of the TS command may destroy the calibration of the unit which can only
be restored by using laboratory calibration instruments in a controlled
environment. An input signal must be applied when using this command.
Trim Zero (TZ)
The Trim Zero command is used to load a value into the Output Offset
Register (Figure 2.1) to null out an offset in the output data. It may be used
to trim offsets created by sensors. It may also be used to null out data to
create a deviation output.
Example: Assume a D1511 bridge input module is being used with a load
cell for weight measurement. An initial reading of the load cell with no weight
applied may reveal an initial offset error:
Command: $1RD
Response: *+00005.00
With no weight applied, trim the output to read zero. To trim, use the TZ
command and specify the desired output reading:
Command: $1TZ+00000.00 (zero output)
Response: *
The TZ command will load a data value into the Output Offset Register to
force the output to read zero. The module will compensate for any previous
value loaded into the Output Offset Register. If another output reading is
taken, it will show that the offset has been eliminated:
Command: $1RD
Response: *+00000.00
Although the TZ command is most commonly used to null an output to zero,
it may be used to offset the output to any specified value. Assume that with
the previously nulled load cell system we performed this command:
Command: $1TZ-00100.00
Response: *
The new data output with no load applied would be:
Command: $1RD
Response: *-00100.00
The load cell output is now offset by -100.
The offset value stored by the TZ command is stored in nonvolatile memory
and may be read back with the Read Zero (RZ) command and cleared with
the Clear Zero (CZ) command.