DH-485 Network

[MUITECstudent 0]

Hello all: A while ago, my partner Sean and I (college students) had posted on the forums for help setting up our DH-485 network. We are trying to use the MSG command between PLCs. Is there a way to use it to turn on/off an output? We have tried a few different techniques, but no success. Is there a trick to it? We have tried sending an integer (N7) from one PLC to another, but this does not work. Under the setup menu, what do we need to put under the following blanks: ----------------- Write PLC: This Controller: Data Table Address____________ Size____________ Target Device: Data Table Address____________ Local Node Address___ (is this the node that we want to send the value to? ----------------- Read PLC: This Controller: Data Table Address____________ Size____________ Target Device: Data Table Address____________ Local Node Address___ (what would this be for?) ----------------- Please let us know what we should try, or possibly, post a link to some sample code on the web. Many Thanks! -Teo & Sean Millersville University ITEC students

[BobLfoot 302]

Writing N7:0 to another PLC and then Reading it back to your local plc gives it no chance to change. I suggest you try the following. Use two PLC's we'll call them PLC A abd PLC B PLC A will be node #1 on the Network PLC B will be node #2 on the Network Create an N7 Integer file with 20 elements in each PLC For PLC A enter the following: Write PLC: This Controller: Data Table Address___N7:10_________ Size____10________ Target Device: Data Table Address___N7:10_________ Local Node Address__2_ (this the node that you want to send the value to? ----------------- Read PLC: This Controller: Data Table Address___N7:0_________ Size_____10_______ Target Device: Data Table Address____N7:0________ Local Node Address__2_ This makes any value in PLC A in registers N7:10 thru N7:19 appear in PLC B at those addresses. and any value in PLC B in registers N7:0 thru N7:0 appear in PLC A. Try it an see how that goes and post back. Edited 2 Nov 2006 by BobLfoot