Search results

" will these dual ethernet interfaces be able to work as redundant ?" It depends how they are configured; do you know the IP addresses ?

I suppose the short answer is maybe... You have not given details of the remote unit working platform - let us assume it's serial data at 9600 baud. You have not given details of the SCADA network. let us assume it's TCP/IP on fibre. So you need a serial to fibre converter which can handle...

Years ago, when a UPS system was a complete disaster, had a PLC and subsystem running on 24vDC battery set being permanent charged on what was effectively a DC PSU. Thinking of the long term effects of constant charging {and the PSU o/p being adjustable}, the charging voltage was set to 26.5vDC...

In my day Hall Effect either detected or it didn't - no inbetween; but now there is a variety of devices eg: https://docs.rs-online.com/4640/A700000006406707.pdf

Good for You !

Your link is to user information, doesn't give comms connection details. The link below is to the Manual - you have register for access to it...

You are correct with RS-232 but we would use twisted pair anyway ! At the time when we made all our comms cable because hard to purchase and /or just not available in a particular format, microphone cable used to be used simply for the number of surplus reels we had.

worse especially with untwisted wires under the shield Some installers run 500m of cable then find there is 20-30vAC at one end and nothing at the other. Then check to find the run is on traywork lying adjacent to power cables..... If you 'throw' a magnet across 2 wires running adjacent to...

I assumed {above post} that your connecting cable has the screen connected at both ends. Now imagine this scenario: - Disconnect the earth connection on your VFD. It is now earthed (grounded) through your cable. - Disconnect the screen/shield/drain on your cable, your VFD metalwork is now...

Could well be a grounding issue - not necessarily surge. Serial cables are generally earthed both end by the screen. Also connected to the casing which may connect to equipment metalwork. Disconnect one end with multimeter see if there AC or DC voltage measurable between cable earth and...

I also have no experience with these products, but the time I was involved with Rockwell motion controllers was a fast learning curve. The controller would sit there and do absolutely nothing (no error codes) because the motors weren’t connected and the proximity switches addressed in software...

“How do you measure 3.5 character times back then on a PLC” YOU DON’T ... In my day it was oscilloscope - now it’s very high speed oscilloscope or high spec data analyser at the baud rates you have quoted. For a fixed baud rate you can work out mathematically character timings, if that’s what...

"Modbus was implemented to be simple and straightforward, and in the 1980’s it was No!" It is a statement of historic fact that you can't change. Clearly you are not 'listening' to what I am saying. Your last posting is all about speed and what has PLC scan time to do with comms link timing ...

Your conclusion is in my opinion incorrect; Modbus was implemented to be simple and straightforward, and in the 1980’s it was. By comparison, Siemens ‘library’ comms for the S5 then the S7 were in comparison, horrendous. Because of this Modbus historically has become one the most famous, well...

You appear to be working with a version of Modbus which is exclusive to Direct Automation. This is ironic for a similar Modbus link, the op suggests there should be a standard Modbus protocol ! So you are entirely reliant on the integrity of Direct Automation.; I have never worked with Direct...

Has your SLC500 series PLC a DH-485 connection? Has your Panelview 550 a DH-485 connection? If yes to both - where would you wire the screens ? and the spare cores ? What’s the length of cable and would it be in an industrial environment ? Screened 2 core (twisted pair) or preferably armoured...

Modbus a time sink - no it isn’t ! Modbus rtu link as the abbreviation suggests started as a modem protocol for remote stations. It just worked. Using Allen Bradley PLC2/5/SLC5 made the 16bit architecture easy with remote devices whose name / type / manufacture you never heard of - again it just...

"What are the applications where Exd, Ex'e' and Ex 'i' Junction boxes are used?" Where explosives gases are floating around designated areas - customer sites generally "How to differentiate between these 3?" You appear to be at the bottom of a very steep learning curve...

1. Use different float switches - there are plenty on the market with high rating microswitch. 2. Employ a cheap small PLC which will give flexibility on float switch and v/f (volt free) output for motor starter. Option 2: Thinking of the Siemens Logo ! which has a good instruction set, easy to...

https://control.com/forums/threads/modbus-tcp-ip-client-automation-direct-productivity-3000-series.49820/ Mindful of the above, can you also increase the number of devices that may be addressed and include the self-assembly data arrays which would help in so many ways.