NETwork DDE

Is it possible to write a word to a plc from excel through NetworkDDE
using RSlinx???????????

This is from the RSLinx Help File...

The following macro writes a value to N7:0 in a PLC-5 using the RSLinx topic, testsol: This routine will write a word from Excel file RSLINXXL.XLS, DDE_Sheet tab, cell D7:

Sub Word_Write()

'open dde link: testsol=DDE Topic

RSIchan = DDEInitiate("RSLinx", "testsol")

'write data thru channel

DDEPoke RSIchan, "N7:30", Range("[RSLINXXL.XLS]DDE_Sheet!D7")

'close dde channel

DDETerminate (RSIchan)


End Sub

b

DDE and NETWORK DDE are not the same thing.

With NETDDE, you can get data from some plc to a pc with rslinx and over many pc without rslinx.
Data is put on .xls file


NETWORK DDE

DATA SHARE read data
| PLC | ----> | PC WITH RSLINX | -----> | PC WITHOUT RSLINX |


This is interesting to give information of our equipment over all pc in the plant without rsview client or another scada.

I know than i can write with DDE but the pc must having rslinx.

My problem is than i can read from pc without rslinx but cannot write.

It is possible?

You do not want to give everyone the ability to write to the PLC do you? Couldn't 5 people all change the same value at the same time etc? Looks like a fight waiting to happen. Just a question.....

netdde???

I've tried a bit of data gathering with netdde. It failed spectacularly. It would sporadically work correctly but not well enough to rely on. Another network dde server such as wonderware might work much more reliably.

$0.02

I guess I should ask what you want to achieve with this Excel spreadsheet on your network? Here we save the DDE linked sheet as a Webpage every minute with a macro, and everyone on our intranet is linked to the web page with Internet Explorer. But you must want some kind of remote control if you want to write to the PLC.

n

I don't want to read or make a webpage, i want to write on netdde.

Have you ever tried to write on netdde??? Or have you ever tried to read on netdde????

Sorry for asking! No I haven't. I was just trying to share ideas. I don't know exactly what you are trying to do.