Dear David, We have been running 4D as front end to plc's for many years.
Communication has varied over the years. At first we based the communication of the old version of OPC (Ole for Process Control). This was based on COM and DCOM in Windows. It was a bit tricky and we were depending on many pieces of software (and windows only). Later we built our own UDP communication over ethernet. This has worked very well and been stable supporting both mac and windows as HMI. We are supporting plc's based on CoDeSys and the iec 1131 programming framework. We have not tried other frameworks (for instance Siemens, Rockwell). As OPC UA is coming as standard (and I think will be built in.. IoT), I would consider the OPC UA as another option. This version of OPC do not rely upon COM, DCOM and specification talks about TCP and web services. However it is doable and you will get reasonable good response times. This is depending on your needs, but we can live with 4-5 redraws/sec. We have a communication 4D process with global vars and arrays filled and presented in another Process for viewing (HMI) Best Regards Magnus Torell -- View this message in context: http://4d.1045681.n5.nabble.com/Using-4D-as-an-HMI-for-a-PLC-tp5746900p5746912.html Sent from the 4D Tech mailing list archive at Nabble.com. ********************************************************************** 4D Internet Users Group (4D iNUG) FAQ: http://lists.4d.com/faqnug.html Archive: http://lists.4d.com/archives.html Options: http://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
