Interface
Pin
Description
8
NC
Not connected
Shield
Cable shield
Functional earth
2.5.4.2.2 Modbus RTU connection details
The Modbus RTU protocol is implemented in the AC500 processor modules.
Modbus is a master-slave (client-server) protocol. The client sends a request to the server(s)
and receives the response(s).
Available serial interfaces can work as Modbus interfaces simultaneously.
The Modbus client operating mode of an interface is set with the function block
COM_MOD_MAST.
Table 188: Description of the Modbus protocol
Parameter
Value
Supported standard
Number of connection points
1 client
Max. 1 server with RS-232 interface
Max. 31 servers with RS-485
Protocol
Modbus
Operating mode
Client/server
Address
Server only
Data transmission control
CRC16
Data transmission speed
From 9,600 bits/s to 115,200 bits/s
(see
Encoding
1 start bit
8 data bits
1 or 2 stop bits
1 parity bit (see
Max. cable length for RS-485 on serial inter-
face option board used on the CPU.
1.200 m at 19.200 baud
Point-to-point with RS-232 or bus topology with RS-485. Modbus is a master-slave protocol.
For further information on Modbus see chapter .
2.5.5 Handling of accessories
This section only describes accessories that are frequently used for system assembly, connec-
tion and construction. A description of all additional accessories that can be used to supplement
AC500 system can be found in the Hardware PLC device description.
2.5.5.1
MC5102 - Micro memory card with micro memory card adapter
● Solid state flash memory storage
Technical data
Bus topology
System assembly, construction and connection
AC500-eCo > Handling of accessories
2022/01/31
3ADR010278, 3, en_US
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