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UMG 96-PA
/
UMG 96-PA
MID
49
13.11 Communication in the bus system
13.11.1 RS485
Data from the list of parameters and measured
values can be accessed from the MODBUS RTU
log with CRC check at the RS485 interface (see
chapter 12.1 on page 34).
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 order of the bytes is high byte before low
byte (Motorola format).
Transmission 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 more information on configuring the
interface, refer to chapter 12 “
ConfiiuratFon /
CommunFcatFon
”.
Example: Reading out the voltage L1-N
The voltage L1-N is stored in the measured value
list under address 19000. The voltage L1-N is
available in FLOAT format.
In this example, 01 is assumed as the device
address.
The “Query message” then appears as follows:
Designation
Hex Remark
Device address
01
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 may then appear
as follows:
Designation
Hex Remark
Device address
01
Address=1
Function
03
Byte counter
06
Data
00
00hex = 00dec
Data
E6
E6hex = 230dec
Error check
(CRC)
-
The voltage L1-N returned by the address 19000
is 230 V.
