• Modbus on Saia PCD®


Modbus is communications protocol based on a master/slave or client/server architecture. It is widely used and supported by many manufacturers and devices. In many cases, therefore, Modbus is the common denominator for exchanging data between different devices and systems.

The Modbus driver is implemented in the firmware of the PCD1.M2, the PCD2.M5 and all PCD3 controllers. The configuration of the driver is done by FBoxes or in IL. The physical layers supported are RTU, ASCII (both on RS-485 or RS-232), UDP/IP and TCP/IP.


System Catalogue : Modbus

Extract 26-215_B0262 System Catalogue : Modbus

Modbus with Saia PCD®

ENG18 .pdf 0.54 MB Download
FRA18 .pdf 0.54 MB Download
GER18 .pdf 0.54 MB Download
ITA18 .pdf 0.54 MB Download

Modbus User Interface Document

Manual 26-866 Modbus User Interface Document

ENG04 .pdf 1.59 MB Download
FRA04 .pdf 1.41 MB Download
GER04 .pdf 1.46 MB Download

Good to know

A program example can be found in the Getting Started section of this page.
The FBoxes for Modbus are automatically installed with PG5 2.0 but need to be licensed.
For older PCD systems (such as the PCD2.M170 or the PCD1.M1x5) a pure FBox solution from the company Engiby exists

PG5 2.0 / Modbus

  • Why the Modbus communication over Ethernet between a Saia PCD and a Siemens S7-314C-2 does not work correctly? (FAQ #101973)
  • How to install the software "Serialtest Async"? (FAQ #101612)
  • How to interpret a Modbus over IP telegram in Wireshark? (FAQ #101441)
  • Is it possible to define a minimum delay between two Modbus requests? (FAQ #101423)
  • How to connect a TME Ethernet Thermometer to a PCD over Modbus? (FAQ #101411)
  • Is it possible to use port 502 TCP as Server and access port 502 as client on the same PCD? (FAQ #101334)
  • What are the differences between Modbus library $2.6.104 and 2.6.220? (FAQ #101295)
  • Correspondence between: Modbus Saia PG5® & Modbus Engiby (FAQ #101203)
  • Can I stop Wireshark based on a specific condition (e.g. Ether-S-Bus communication has stopped)? (FAQ #100840)

The requested software / document is no longer marketed by Saia-Burgess Controls AG and without technical support. It is an older software version which can be operated only on certain now no longer commercially available products.