Introduction
The CJ2 CPU supports CIP messaging via built in Ethernet/IP port or CJ1W-EIP21(S). However it can be complicated generating the message structure to send the messages as desired. This article give a brief summary of how to use custom CIP messaging function blocks. Note that these blocks have not undergone the same validation as the built in functions in cx-programmer.
CJ_EIP01_UCMM_Set
This function block sends an information write command in an explicit message (Set Attribute Single, Service Code: 10 hex).
CJ_EIP02_UCMM_Get
Sends an information read command in an explicit message (Get Attribute Single, Service Code: 0E hex).
CJ_EIP03_UCMM_Cmnd
Sends an explicit message with the defined service code.
Below is an example program showing how you may use the function blocks to read a attribute from a MX2 EIP card, write an attribute to a MX2 EIP card and use a command to read memory from a CJ controller (service code 1D).