janitza UMG 96-S2, User Manual And Technical Data

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UMG 96-S2 www.janitza.com
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9. Communication via the RS485 interface with the
Modbus RTU protocol
Via the Modbus RTU protocol with CRC check
on the RS485 interface, you will attain
·Data from the parameter list and
·Measured values from the Modbus address list.
Setting range of the device addresses: 1 .. 247
Standard
setting: 1
Standard setting for baud rate in kbps: 38.4
Modbus functions (slave)
04 Read input registers
06 Preset single register
16 (10Hex) Preset multiple registers
23 (17Hex) Read/write 4X registers
The order of the bytes is high byte before low
byte (Motorola format).
Transmission parameters:
Data bits: 8
Parity: odd, even, none (1 stop bit), none (2 stop
bits)
Stop bits (device): 1/2
Stop bits, external: 1/2
Number formats: short 16 bit (-2
15
.. 2
15
-1)
float 32 bit (IEEE 754)
NOTE
·The device does not support a broadcast
(address 0).
·The telegram length may not exceed 256 bytes.
Example: Reading out the voltage L1-N
The voltage L1-N is archived
·in address 19000 of the measured value list.
·in FLOAT format.
The device address for the device is accepted
here with address = 01.
The “Query message” then appears as follows:
Designation Hex Remark
Device address 01 UMG 96-S2, address = 1
Function 03 “Read holding reg.”
Start address Hi 4A 19000dec = 4A38hex
Start address Lo 38
Number of Hi values 00 2dec = 0002hex
Number of Lo values 02
Error check (CRC)
-
The “Response” of the device can then appear
as follows:
Designation Hex Remark
Device address 01 UMG 96-S2, address = 1
Function 03
Byte counter 06
Data 00 00hex = 00dec
Data E6 E6hex = 230dec
Error check (CRC) -
The voltage L1-N read by the address 19000 is
230 V.