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simon Ong SK

RS485

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Hi guys: Any one did this before? Connect multiple Scale Indicator by RS485 to SCU41? Using CX Protocol--Protocl Macro? or TXDU/RXDU??? Do anyone has sample Protocol and PLC Program? I came across some of the posted sample but were between PLCs. Thanks In Advance. Simon

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If the scale indicators have Modbus RTU protocol, it is easy. Ther is a sample Modbus program for CX-Protocol in the Omron downloads section on this site. It works very well.

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Yeah, I did have that Modbus Protocol. The Problem is the Scales are with RS232/RS485. To save some $$$$, RS485 is the only choice. I took a hard look at the CX Protocol Manual, where the Address can be used to identity the "Node" or address of the individual Equiments. Is that right. Does that meant I should write say X number of repeating protocol by incrementing the address. Or Should I write at PLC by incrementing the Send portion of the PMCR Function ? What kind of Time lag should I see?

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Try this RXD/TXD

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What are the scale make ? I have developed one for RANGER scales that can talk to a number of scales on and RS485 network. You do need to set the Unit/Node numbers for each scale on the Network for starters. For cx-protocol to work you will need a scu41 module/card. Secondly match the baud. num stop bits, parity settings for the PLC comm's units. and set it to use protocol macro. develope protocol. compile & download. use trace tool to debug. Try this download Weigh Scale Protocol Example

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Yes, SCU41 come in mind. As there may be a total of 27 Metler Toledo Scale to be used. Out of it 25 will be link with RS485 the remaining 2 with RS232. As The two unit of scales with RS232 are much critical than the 25unit. The Protocol Macro look more suitable. As the Protocol from Wombat look like the one. The Repeat (RSET/R(1)), can be program to performed as many time as possible ? Like at PLC program by increasing the "Node" number at the Send portion of the Protocol Macro?? say: -----++ D100?? then the Protocol Macro will read the next Unit/Node?? Am I correct to say that?? Or is there any other method? Thanks again for the info.

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Use and set up the protocol instance as follows:

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