V700 and mod bus communication

[Egyed Károly]

Hi,

Modbus RTU (RS485) Check Network Status

We have created a new plc prg. It has worked, but we wanted to unload a new version by remote and this projekt was broken.  Now we have not communication beetwen plc and sensor-motor electronic (Leadshine AC Servo Drive EL6-RS750Z).

What can be the problem ?

 

[Ausman]

There's not enough information here as there could be any number of things wrong.

My understanding of what you have said is that you made a new program for an existing machine.  The machine WAS working ok but now you've downloaded the new program the machine no longer communicates to the Leadshine.

You need to carefully go through the old modbus parameters and check that everything is the same as before.  Ensure the download is a "download and burn" at the very least, then reboot the plc, and perhaps do an Init and Reset as well after the reboot.

Alternatively, if it is a new plc, or a new machine and is remote, then perhaps jumpers on the plc need setting to a correct position by someone at the remote end.

cheers, Aus

[Egyed Károly]

Thank you. We have changed the plc. Also we have made reset + init; turned off-on.; checked the communication cabel. But no communication !

[kratmel]

V700 has one RS232/RS485 port.

If you connect to this new PLC via Ethernet - please check RS232/RS485  DIP SW on back side of plc. Maybe you need to set RS485 mode for port.

If you connect to this PLC via USB - RS232/RS485 port is disabled!!! (USB use this port1 when USB connected).  You must disconnect USB and restart PLC for communicate via RS485 with correct settings to RS485 via DIP SW.

Please post how the Leadshine is connected and check - is the communication settings for PLC and Leadshine the same.

If PLC has RS485 add on card  (PORT2) connected to Leadshine - please check port configuration in your project.