DVP-ES3 Series Programming Manual Only the function codes listed above are supported. Other function code setting values, such as 0, are invalid (including communication address, length and the start register), and the instruction executes the data exchange function based on the original communication parameter settings. 4. When you select 16#17 (for reading and writing synchronously) in S 4 (the function code for reading), the operand S 8 (the function code for writing) is processed as invalid and 16#17 is automatically processed for writing data. 5. The parameter values specified by the instruction are valid only while PLC is running.
If you cycle the power on the PLC, the data in the data exchange table set in HWCONFIG are taken as default values. If you want to modify the values for parameters, use this instruction. 6. You can use the instruction to immediately set the parameters for the communication connection when the data exchange function is not running. The new communication parameters are not used until the next cycle if the data exchange function is running; however, the instruction changes the communication parameters for the connection number. For example, while the data exchange function is running with the parameters set for connection 3, you can specify new the parameters for connection 3.
The new parameters are not used until the next cycle when connection 3 starts. 7. The instruction only allows you to change the communication parameters. Refer to the following table for the flags to start and close the communication connection function if you use the PLC program to perform those functions. _6 When you set the automatic scan function through ISPSoft, the start/stop flag of the connection number automatically updates the start/stop state once after the data exchange function finishes executing the scan. The following table describes the SM flags. 6-582 SM No.
Attribute Explanation for COM1 data exchange parameters SM750 R/W Enables data exchange SM752–SM783 R/W Enables data exchange connections 1–32 SM784–SM815 R Reading success for data exchange connections 1–32 SM816–SM847 R Error flags for data exchange connections 1–32 SM No. Attribute Explanation for COM2 data exchange parameters SM862 R/W Enables data exchange SM864–SM895 R/W Enables data exchange connections 1–32 SM896–SM927 R Reading success for data exchange connections 1–32 SM928–SM959 R Error flags for data exchange connections 1–32