UMG 96-PA
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52
13. 11 Communication in the bus system
13. 11. 1 RS485
The data can be accessed from the param-
eter and measurement value list (cf. Section
"
Configuration / Communication
“) via the
MODBUS RTU protocol with the CRC check
on the RS485 interface.
Modbus functions (Slave)
03 Read Holding Registers
04 Read Input Registers
06 Preset Single Register
16 (10Hex) Preset Multiple Registers
23 (17Hex) Read/Write 4X Registers
The byte order is highbyte before lowbyte
(Motorola format).
Transfer parameters
Data bits:
8
Parity:
odd
even
none (1 Stopbit)
none (2 Stopbits)
Stopbits (UMG 96-PA): 1 / 2
Stopbits, external:
1 / 2
Number formats
short
16 bit (-2
15
.. 2
15
-1)
float
32 bit (IEEE 754)
For further information about the interface
settings, refer to Section 12 "
Configuration /
Communication
."
Example: Read-out of voltage L1-N
Voltage L1-N is saved in the measurement
value list at the address 19000. Voltage L1-N
is available in FLOAT format.
In this example, 01 will be used as the device
address.
The "Query Message" will then appear as
follows:
Name
Hex Comment
Device address
01
Address=1
Function
03
"Read Holding Reg"
Starting ad-
dress Hi
4A
19000dez = 4A38hex
Starting ad-
dress Lo
38
Number of val-
ues Hi
00
2dez = 0002hex
Number of val-
ues Lo
02
Error Check
(CRC)
-
The "response" of the device may look as
follows:
Name
Hex Comment
Device address
01
Address=1
Function
03
Byte counter
06
Data
00
00hex=00dez
Data
E6
E6hex=230dez
Error Check
(CRC)
-
The voltage L1-N read back from the address
19000 is 230 V.
Summary of Contents for UMG 96-PA
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