212
saia-pcd.com
3330
PCD3.M
Modbus-ASCII / RTU
Communication & interaction
2.6.3
Modbus
Modbus is a communication protocol based on a master/slave or client/server architecture. It is wide-spread and supported by many
manufacturers and devices. In many cases, Modbus is therefore the common denominator for transferring data between different
devices and systems.
Modbus with Saia PCD®
Modbus comes in three forms:
`
Modbus ASCII data are transmitted in ASCII format via serial
interfaces (RS-232, RS-485).
`
Modbus RTU data are transmitted in binary format via serial
interfaces (RS-232, RS-485).
`
Modbus-TCP data are transferred in TCP/IP or UDP/IP packets
via Ethernet.
Supported Modbus function codes
1
Read Coils
2
Read Discrete Inputs
3
Read Holding Registers
4
Read Input Registers
5
Write Single Coil
6
Write Multiple Coils
7
Write Single Holding Register
8
Write Multiple Holding Registers
S
Convenient Fulpa FBoxes or CSF commands are available for configuring
and programming the exchange of data.
e
Together with the integrated automation server, external systems can also
be easily linked to master Web+IT automation environments via Modbus.
The Modbus protocol is supported in the Saia PCD® COSinus
operating system by all Saia PCD1.M0_, Saia PCD1.M2_,
Saia PCD2.M5_ and Saia PCD3 controllers. Client and server
functionalities are available for all types of protocol.
Ethernet interfaces and serial interfaces (RS-232 and/or RS-
485) are already included in the PCD controller basic devices.
Additional plug-in interface modules can be used to operate
up to 9 serial Modbus interfaces per PCD system.
Number of connections
Each Saia PCD® system is able to establish up to a maximum
of 26 connections. Of these, the Saia PCD® controller is able
to use a maximum of 10 for client connections. The remaining
connections can be used as server connections to the same
Saia PCD® controller.
Media Mapping:
adjustable by the user
Mapping Areas:
max. 10 pro UID
Number of servers: max. 4 per PCD system
Number of unit IDs: max. 10 pro PCD-System
Number of channels: max. 10 pro PCD System
Application example
Modbus-TCP
Ethernet
PCD2
PCD1
PCD3
