adccommunitymod (AutomationDirect) asked a question.
Created Date: April 28,2005
Created By: glenncovington
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I am looking at a project to network the dust collection systems at our plant (approx. 1M sq. ft.) There are six separate dust systems. The goal is to have control and monitoring stations at 3 different locations in the plant. There is a plantwide LAN with fiber backbone. I was thinking of using Terminator I/O at each motor control center and a master PLC located at the main control location. I would want some sort of Touchpanel HMI (redundant for all three locations) to communicate to the master PLC to start and stop operations. 1. Can the plant LAN be used to connect all the equipment? 2. What level of processor will be needed to the communications over the LAN? Thanks for any assistance. Glenn
Created Date: April 28,2005
Created by: PCallaghan
Terminal I/O needs to be on it's own network with the PLC it is connected to. It is possible to place it on the plant LAN from a physical standpoint, but from an application standpoint it is not. The communication between the Terminal I/O and the PLC will flood the network and you will end up with communication time-outs. When Terminal I/O has a communication time-out the outputs turn off. Even if you had a separate LAN for the Terminal I/O and PLC I wouldn't go this route with your application.
I would place a PLC at each dust collector station then network the PLCs together. If possible place the PLCs on their own network, if not possible transmit as little data between the PLCs as possible and program logic into the PLCs to handle times when you will lose communication between the stations. Also by placing a PLC at each location you can connect a HMI (control and monitoring station) directly to the PLC, instead of placing it on the network.
What processor you need will more than likely come down to how much I/O you need.
Created Date: April 28,2005
Created by: glenncovington
The problem I am wrestling with is the distance from the desired control HMI stations and the actual location of the motor starters. I wouldn't mind a small plc at each motor control center (6 total) but how to get the control stations (3 total) to all talk to the 6 plcs without running a lot of cable?
Created Date: April 29,2005
Created by: marksji
Put all 6 PLCs on a LAN with the 3 HMIs. Each HMI can run identical software that talks to the 6 different PLCs.
Created Date: April 28,2005
Created by: glenncovington
I am looking at a project to network the dust collection systems at our plant (approx. 1M sq. ft.) There are six separate dust systems. The goal is to have control and monitoring stations at 3 different locations in the plant.
There is a plantwide LAN with fiber backbone. I was thinking of using Terminator I/O at each motor control center and a master PLC located at the main control location. I would want some sort of Touchpanel HMI (redundant for all three locations) to communicate to the master PLC to start and stop operations.
1. Can the plant LAN be used to connect all the equipment?
2. What level of processor will be needed to the communications over the LAN?
Thanks for any assistance.
Glenn