Modbus Plus programming
Examples of Exchanges on Offset Networks
At a Glance
22
The following illustration shows the two types, which are processed subsequently:
Modbus Plus
Premium
13
Quantum
61
BP85
Bridge Plus
12 30
15 25
Quantum
62
Quantum
BP85
Bridge Plus
4 7
Quantum
9
22
Slave
A
1
Bridge multiplexer
2 3 4
Modem
Modem
Master
A
Modem
Slave
113
Slave
69
BP85
Bridge Plus
208
TLX DS COM PL7 xxE
Example 1
Modbus Plus programming
Reading 120 internal words to address 80 of the Quantum station at the local address of 62 using a TSX Premium requires: l l l the routing path to access the Quantum station: 61, 30, 22, 62, 0.
the reading request code: 16#36.
the actual size of data to be transferred (memorized in %MW603): 10 bytes.
SEND_REQ(ADR#0.1.61, 16#36, %MW300:5, %MW450:120, %MW600:4)
Coding of the data to be transferred:
Parameters
%MW300
%MW301
%MW302
%MW303
%MW304
No data
Values
0x161E
0x003E
0x0768
80
120
Description
Second and third changeover addresses (30, 22)
Fourth and fifth changeover addresses (62, 0)
Segment 104 and type 7 (depends on the type of variable to be read or written)
Address of the first internal word to be read in the Quantum station
Size of data to be read (in words)
Note: After the execution of the SEND_REQ function, it is necessary to reclassify the bytes in the correct order.
TLX DS COM PL7 xxE
209
Modbus Plus programming
Example 2 Writing 50 internal words to address 560 of slave 113 connected to port 4 on the multiplexer bridge using a TSX Premium requires: l l l l l the routing path to access the slave: 61, 25, 4, 113, 0.
the reading request code: 16#37.
the actual size of data to be transferred (memorized in %MW603): 110 bytes.
the values of the data to be written (memorized in %MX306 to %MW354).
the response (memorized in %MW450:1): does not contain any data to be received, but should have a minimum length of a word.
SEND_REQ(ADR#0.1.61, 16#36, %MW300:5, %MW450:120, %MW600:4)
Coding of the data to be transferred:
Parameters
%MW300
%MW301
%MW302
%MW303
%MW304
%MW305 to
%MW354
%MW603
Values
0x0419
0x0071
0x0768
560
50
110
Description
Second and third changeover addresses (25, 4)
Fourth and fifth changeover addresses (113, 0)
Segment 104 and type 7 (depends on the type of variable to be read or written)
Address of the first internal word to be written in the Quantum station
Size of the data to be written (in words)
Data to be written
Actual size of the data to be transmitted with this function (in bytes)
210
TLX DS COM PL7 xxE
