Ezplc PLC

[TonyReo]

I am trying to communicate with an EZPLC PLC via Ethernet.

I have the PLC setup with an IP address (192.168.1.1) and can ping it successfully.

When I try to initialize the port via the NI ModBus vi I get this error:

Error -1073807343 occurred at Property Node (arg 1) in MB Serial Init.vi->Untitled 1

Possible reason(s):

VISA:  (Hex 0xBFFF0011) Insufficient location information or the device or resource is not present in the system.

The VISA resource name I am using is:

TCPIP::192.168.1.1::INSTR

I can’t figure out what I’m doing wrong.

Anyone have any suggestions?

Here is the code I am using: (pretty basic)

[Elizabeth_K.]

Are you able to dig down into the Modbus VI and see where this error is occurring? Does this device communicate over ethernet modbus?

Regards,

Elizabeth K. 

National Instruments | Applications Engineer | www.ni.com/support 

[TonyReo]

Hi Elizabeth,

Yes, the EZPLC supports modbus as either master or slave, according to their website.

I have also tried to write to the PLC via the VISA vi in place of the modbus vi and get the same error.

Tony

[Elizabeth_K.]

Tony,

I believe that you are using the wrong set up Modbus library VIs. The VI that is pictured on the first post is for Modbus Serial devices. You mentioned that your device is a Modbus Ethernet device. I would recommend taking a look at the MB Ethernet Example Master.vi, which is in the Modbus Library. You may also find the help useful. 

Regards,

Elizabeth K. 

National Instruments | Applications Engineer | www.ni.com/support