FAQ03620 of Programmable Controllers FAQ

Yes, the latest Serial Communication Units can use non-procedural communications.
The TXDU and RXDU instructions for non-procedural communications can be used with CS1/CJ1-series Serial Communications Units with unit Ver.1.2 or later. In this case, the CPU Unit must be unit Ver.3.0 or later.

The TXDU and RXDU instructions for non-procedural communications can be used with CS1-series Serial Communications Boards with unit Ver.1.2 or later. The unit version of the CPU Unit is not a factor.

In previous configurations, non-procedural communications were only possible using the built-in RS-232C port on a CPU Unit using the TXD and RXD commands.