topic Re: server expolrer in LabVIEW

server expolrer

mom — Fri, 13 Apr 2007 06:00:01 GMT

dear sir,

I am using labview 7.0 with DSC module. Now i want to check communication between 10 instruments from computer in server explorer for that i am using rs485 bus. My each instrument is able to respond between 100ms. For this please suggest me for pollrate and time out settings.

falgandha

Re: server expolrer

AdnanZ — Fri, 13 Apr 2007 21:29:25 GMT

Hi falgandha,

I am not sure if I understand your question here. Are you talking to an OPC server which is communicating with these instruments over the RS485 bus? Or, are you doing something else?

Re: server expolrer

mom — Mon, 16 Apr 2007 03:44:01 GMT

hi,

i am asking for only with opc servers which is communicating with these instruments via rs 485 bus

falgandha

Re: server expolrer

mom — Wed, 18 Apr 2007 04:21:20 GMT

hi,

i am asking for only with opc servers which is communicating with these instruments via rs 485 bus

falgandha

Re: server expolrer

mom — Wed, 18 Apr 2007 06:53:30 GMT

dear sir,

please first understand my application.

i want to check my 32 instruments in server explorer for communication.These instruments are usin RS485 communication protocol to communicate with PC. Each instrument is capable to respond within 100miliseconds after each query received. For these 32 instruments iam making .lpd file separately. When i start communication with these instrument i am getting lots of alarm messages in Industrial automation opc server window as no communication response from modbus secondary. Before that i have tried it for only one instrument it is working well. So now i am facing the problem for 32 instrument. So what can i do for that. If there will be any software in which i can check these 32 instruments together please suggest me for that. So i can confirm from my instrument side that they are ok. Also suggest me for poll rate, receive timeout settings in .lpd file for 32 instrument.

thanking you and waiting for your best reply.

falgandha

Re: server expolrer

AdnanZ — Wed, 18 Apr 2007 20:14:23 GMT

Hi falgandha,

I hope you are doing well today! I need to understand how you are doing this communication with Modbus. Are you creating a single Modbus object and trying to communicate with all instruments? If so, how you are you changing the address field? Or, are you creating a Modbus object for each instrument. This is what I am assuming you are doing and this will definitely cause issues since all those objects are using a single serial port and that is definitely not possible to do since it is a resource conflict.

I would create a single Modbus object and use the Modbus Library (which is available for free) to change the address field of the object to communicate with all the instruments. I don’t think this is possible to do with LabVIEW DSC and that is why you will need to use the library.

Server Explorer is not the right way to check for communication with all 32 instruments. Also, is there a reason you are using LabVIEW DSC 7.0? We have upgraded to LabVIEW DSC 8.2.1 and won’t be supporting 7.0 anymore.

The poll rate setting depends on the application. The timeout settings should usually be double the time it takes to communicate with an instrument.

If you have any other questions, please be sure to let us know.