Model: LC5296-XP-DC
Doc. Ref. no.:- m61D/om/401
Issue no. 05
User’s Manual
Page 24 of 31
After applying appropriate Input from
the calibrator source, press ‘INCREMENT’
OR ‘DECREMENT KEY’ to bring the actual process value on display.
Example:-
At zero calibration reading expected on the display is 100 and it shows 107, adjust the
process value to 100 by using ‘DECREMENT KEY’. Now press ‘ENT’ to store the
calibration parameter in non-volatile memory. Similarly one can calibrate Ambient,
SPAN and retransmission parameters.
For calibrating i/p, both zero and span are calibrated. Here
one-shot calibration
technique is used, i.e. the zero and span are calibrated once. Individual zero or span
can also be calibrated; first calibrate zero and then span. While calibrating
thermocouple type input, first calibrate the ambient (if required) and then continue with
the span calibration of the same.
8.2 Procedure for RET-zero and RET-span
For calibrating the retransmission output, both retransmission zero and retransmission
span has to be calibrated. At a time there can be either one or two retransmission
output available. If only one retransmission is used, then calibrate
rtZ1
(retransmission
1 zero)
and
rtS1
(retransmission 1 span)
and if there are two retransmission outputs
available, then calibrate
rtZ2
(retransmission 2 zero)
and
rtS2
(retransmission 2 span)
for second retransmission. No need to feed input while calibrating retransmission o/p.
it is like calibrating using digital trim pot. Only look at the output, display value has no
significance with output generated.
Example:-
At retransmission zero calibration, expected output is 0.00mA and it gives 0.153mA.
Then adjust the output value to 0.153 by using ‘INCREMENT KEY or DECREMENT
KEY’. Now press ‘ENT’ to store the calibration parameter in non-volatile memory.
Similarly one can calibrate retransmission span.
9. COMMUNICATION PROTOCOL–MODBUS RTU
9.1 INTRODUCTION
The unit can be connected in RS-485 communication data link either in multi drop or
repeat mode. Each unit must have unique Serial Number. Entire range of addresses
(1 to 247) may be used. Before starting any communication, choose a baud rate
compatible to the host computer. The serial protocol used is MODBUS RTU.
Function Code for Modbus
CODE NAME
Function
01
Read coil status
Use to read Relay and Digital output status
03
Read Holding registers
Use to read PV, Control, RSP output etc
04
Read input registers
Use to read programmable registers
06
Preset Single register
Use to write programmable register
