OPC / RsLinx / VB5


Thread Starter

Malcolm Moorhouse

I need a very small HMI for a SLC-504, it only needs to read and write to a dozen integer and float registers. We intend to write a small application with VB5 (Enterprise edition) for the interface.

Can any list members advise how OPC via RSLinx could be used with VB5 rather than DDE.

Many Thanks,
Actually, I would recommend skipping the RSLinx method completely. I spent about 2 months on it and never got it to work reliably. I spent about $1000 and bought an ActiveX control from
automated solutions, dropped it into my form, and never looked back. I bought the ethernet version, but a quick check of the web site shows:


a datahighway version, which supports the SLC 5/04 processor. I know there are also others out there that do the same thing, I just had success with this one.


--Joe Jansen
Do not kill yourself, for under $1000, you can get a package from Iconics that will connect to the OPC server(RSLINX) if you have it , if not you can get their OPC server for AB which does not require the RSLINX license. Gives you trending, alarming and graphics. The long term support and maintenance of a home brew can cost you more than a grand easily
Mark Massa

Garnet Tremere


I have an alternative solution to you writing your own code.

We have a product in house that can be used as an HMI talking to your SLC-504 device. It is a HMI that can speak Modbus and DNP at the moment but can be integrated to use another protocol if
desired. If the SLC-504 has a fixed point count, and uses one of the protocols mentioned above a HMI for this device can be created with in a two weeks approximately for delivery, it sounds as though this device has a low point count. The software is called RTView Express, and is intended to be a freeware in which we give to
vendors to put out with their devices. Please visit www.subnetsolutions.com for more information regarding this.

Garnet Tremere
Do you need a PC based system at all ? At Proface we have low cost non-PC touch screen HMI that'd plug straight into the SLC504. If you wanted to link them up to a PC we have an ethernet module for the HMI and server software that'd give you DDE, OPC or direct access from VB or VC via DLL.

Tony Lane, profaceuk.com