Bender COMTRAXX COM465IP - Example: Querying Device Registers

PROFIBUS DP (COM465DP only)
37
COM465IP-COM465DP_D00216_02_M_XXEN/03.2017
5.2.2 Type 2: Querying registers in devices on the bus
5.2.2.1 Example: Querying a register on the RCMS490-D
The RCMS490-D has the BMS address 2. The "Prewarning" menu item is queried. It has the value "50
%". A register has a size of one word.
Request to the gateway:
Response from the gateway:
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8 Byte 9
Byte 10
ID Msg
type
System Device Number
of regis-
ters
Address
high
Address
low
0x00 0x00 0x00 0x00
0x04 0x02 0x02 0x02 0x02 0x22 0x06 0x00 0x00 0x00 0x00
Byte 0: Sequential ID no.
Byte 1: Message type: For this request always 0x02
Byte 2: Subsystem address: 2
Byte 3: BMS device address: 2
Byte 4: Number of registers: 2
Byte 5: Register start address high byte: 0x22
Byte 6: Register start address low byte: 0x06
Byte 7-10: Always 0x00
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8 Byte 9
ID Numb
er of
regis-
ters
Reg. 0
high
Reg. 0
low
Reg. 1
high
Reg. 1
low
Reg. 2
high
Reg. 2
low
Reg. 3
high
Reg. 3
low
0x04 0x02 0x42 0x48 0x00 0x00 0xFF 0xFF 0xFF 0xFF
Byte 0: Sequential ID no.
Byte 1: Number of registers: 2
Byte 2 Register 0 high byte: 0x42
Floating point value 50 = Prewarning 50 %
Byte 3 Register 0 low byte: 0x48
Byte 4 Register 1 high byte: 0x00
Byte 5 Register 1 low byte: 0x00
Byte 6-9 0xFF