SvjatoslavsKrasnikovs Posted July 25, 2017 Report Share Posted July 25, 2017 Hi, I'm running an Arduino-based home automation system. My custom-made Arduino clones are communicating over a RS485 network (configured as 8N1) using Modbus RTU protocol. Thing is that I want to have a reliable, industrial-grade PLC in the network, in order to monitor my Arduino-based sub modules. Basically I need a cost efficient Unitronics PLC capable of connecting to RS485 network, The ladder program is expected to be non memory hungry, also I'm fine with good old 2 line display. The PLC must be able to connect to the RS485 network without the use of any extension modules/communication modules /.etc (native COM port on a screw terminal). Any suggestions? Thank You. Quote Link to comment Share on other sites More sharing options...
MVP 2023 Flex727 Posted July 25, 2017 MVP 2023 Report Share Posted July 25, 2017 The Samba 35 with a RS485 add-on should do the job inexpensively. The Vision 120 or 130 would also do the job for a few dollars less, but the Samba has a MUCH nicer display. The M91 would probably be the least expensive solution from Unitronics, with a 2-line display and built-in 485 port, but uses the U90 Ladder software for programming which can be a bit more cumbersome than the outstanding VisiLogic programming software used for the Vision and Samba lines. Quote Link to comment Share on other sites More sharing options...
SvjatoslavsKrasnikovs Posted July 25, 2017 Author Report Share Posted July 25, 2017 Thank You for the reply. In the case of Samba 35 - what's the least expensive RD485 add-on module I'd need ? In the case of M91 - do I need any RS485 add-on modules for those ? Quote Link to comment Share on other sites More sharing options...
MVP 2023 Flex727 Posted July 25, 2017 MVP 2023 Report Share Posted July 25, 2017 I'm not a distributor so I don't have any price information, but I think there's only one serial port add-on for the Vision and Samba lines, although there may be an isolated port variant as well. As far as the M91 and the V120/V130, I believe the serial port is built in. Quote Link to comment Share on other sites More sharing options...
MVP 2023 Joe Tauser Posted July 26, 2017 MVP 2023 Report Share Posted July 26, 2017 The cheapest way to go is an M91-2-R1 - $230 US. RS485 is built into the COM port. You could also go with a Jazz JZ20-R10 ($140 US) with a JZ-RS4 RS232/485 com port ($99 US). If you don't need any I/O it will be much easier to use a V130-B1 ($269 US) which will allow you to use VisiLogic. U90 software is rather cumbersome when it comes to communications. Joe T. Quote Link to comment Share on other sites More sharing options...
SvjatoslavsKrasnikovs Posted July 26, 2017 Author Report Share Posted July 26, 2017 Does V130-B1 need an rs485 extension module ? Quote Link to comment Share on other sites More sharing options...
Ofir Posted July 26, 2017 Report Share Posted July 26, 2017 V130 has a built-in serial port that support RS232/RS485. (The selection is done via jumper) Quote Link to comment Share on other sites More sharing options...
MVP 2023 Joe Tauser Posted July 27, 2017 MVP 2023 Report Share Posted July 27, 2017 The V130 COM port connection is documented in the Technical Library section- https://myzone-kza3sadj.netdna-ssl.com/wp-content/uploads/2015/12/Vxxx_J_B1_INSTAL_GUIDE_11-151.pdf Joe T. Quote Link to comment Share on other sites More sharing options...
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