Service manual

179Appendix I Using MODBUS Protocol in CAS Profile
Cyclades-TS Installation & Service Manual
APPENDIX I USING MODBUS PROTOCOL IN CAS PROFILE
MODBUS is an application layer messaging protocol for client/server communication which is widely used in the
industrial automation. It is a confirmed service protocol and offers many services specified by function codes,
like reading and writing registers on PLCs.
A protocol converter for the MODBUS protocol over the TCP/IP communication stack (Modbus/TCP) is
implemented in Cyclades-TS and converts Modbus/TCP ADUs from the Ethernet interface to plain MODBUS
message frames over a serial RS-232 or RS-485 interface, and vice-versa, supporting both serial modes (ASCII
and RTU).
FIGURE I.1 - MODBUS APPLICATION