how to configure modbus using LabVIEW?
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From: Michael C on 16 Dec 2005 13:10 Hi Nishant, The library that is available from our website is for LabVIEW 7.1. The files and instructions I posted are for anyone using LabVIEW 8.0<a href="http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=F1582737BACF5CA8E0340003BA7CCD71&p_node=DZ52363&p_source=External" target="_blank">http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=F1582737BACF5CA8E0340003BA7CCD71&p_node=DZ52363&p_source=External</a>
From: styrum on 22 Dec 2005 12:26 Michael C wrote: > Hi Nishant, > The library that is available from our website is for LabVIEW 7.1. The files and instructions I posted are for anyone using LabVIEW 8.0<a href="http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=F1582737BACF5CA8E0340003BA7CCD71&p_node=DZ52363&p_source=External" target="_blank">http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=F1582737BACF5CA8E0340003BA7CCD71&p_node=DZ52363&p_source=External</a> > Did anybody try to set outputs of (AutomationDirect.com) Direct Logic 05 PLC directly from a LabVIEW program using NI Modbus library? I have a dead simple question: What "Starting Address" do I feed to "MB Serial Master Query.vi" to set the outputs? The DL 05 manual is confusing about this. I managed to read the inputs using the same "MB Serial Master Query.vi" with function 2 (Read Discrete Inputs) and address 2048, but can't set the outputs with function 15 (Write Multiple Coils) or any other. With some addresses it sets some coils OK (you can tell, because this VI reads them back as well), but, apparently, those are not the output coils (output lights don't switch)!
From: styrum on 22 Dec 2005 12:27 Did anybody try to set outputs of (AutomationDirect.com) Direct Logic 05 PLC directly from a LabVIEW program using NI Modbus library? I have a dead simple question: What "Starting Address" do I feed to "MB Serial Master Query.vi" to set the outputs? The DL 05 manual is confusing about this. I managed to read the inputs using the same VI with function 2 (Read Discrete Inputs) and address 2048, but can't set the outputs with 15 (Write Multiple Coils) or any other. With some addresses it sets some coils OK (you can tell, because this VI reads them back as well), but, apparently, those are not the output coils (output lights don't switch).
From: Srinivas Kharsada Patnaik on 23 Dec 2005 07:10 actually i found it in a certain example which is already with LabVIEW 7.1. its an example related to Queue control. Its in Queue.llb library named Queue Control Reference Info.vi Thanks
From: Donald on 23 Dec 2005 09:40
Anonymous wrote:Did anybody try to set outputs of (AutomationDirect.com) Direct Logic 05 PLC directlyfrom a LabVIEW program using NI Modbus library? ... With some addresses it sets some coils OK. Anonymous, I haven't tried the NIModbus library (yet), and I tend to only work with holding registers (not coils) in Direct Logic CPUs, but 2048/2049 does seem to be the correct starting address for the output coils (Y0 etc.) from all the docs I've got. Couple of questions: 1) What position is the PLC's Mode switch in? STOP, TERM, or RUN? 2) With what addresses does it set "some coils OK"? Have you tried writing to some internal/memory coils (C0-C777, starting Modbus addr 3072) that aren't used in your PLC program? |