Serial Communication - PCE Instruments UA964801 Betriebshandbuch

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Serial communication

UA964801 equipped with RS485 can receive and broadcast data via serial
communication using MODBUS RTU protocol. The device can be configured only
as a Slave. This function enables the control of multiple controllers connected to a
supervisory system. Each controller responds to a master query only if the query
contains the same address as that in the parameter par. 126 Slave address
The permitted addresses range from 1 to 254 and there must not be controllers
with the same address on the same line.
Address 255 can be used by the master to communicate with all the connected
equipment (broadcast mode), while with 0 all the devices receive the command,
but no response is expected.
UA964801 can introduce a delay (in milliseconds) in the response to the master
request. This delay must be set on parameter 129 Serial Delay
Each parameter change is saved by the controller on EEPROM memory (100000
writing cycles).
NB: changes made to Words that are different from those reported in the following
table can lead to malfunction.
Baud-rate
Format
Modbus RTU protocol features
Selection on par. 127 Baud Rate:
1.200 baud
2.400 baud
4.800 baud
9.600 baud
19.200 baud
Selection on par. 128 Serial format:
8, N, 1 (8 bit, no parity, 1 stop)
8, E, 1 (8 bit, even parity, 1 stop)
8, O, 1 (8 bit, odd parity, 1 stop)
8, N, 2 (8 bit, no parity, 2 stop)
8, E, 2(8 bit, even parity, 2 stop)
8, O, 2 (8 bit, odd parity, 2 stop)
28.800 baud
38.400 baud
57.600 baud
115.200 baud
.
.
User manual - UA964801
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