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- PC reliability?
- Windows, real time
- PID loops
- PCs vs. PLCs
- Replacing people
- MS 'monopoly'?
- Software quality
- Where do we go from here?
- Why pay?
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How to put to master in the same Modbus bus RS485
New Replies:
We manufacture a Gateway that allows two Masters over the same Modbus Slave devices. It is our DX...
By Jerry Miille on 5 October, 2009 - 9:23 am -
You are absolutely correct, only one master "at the same time". It is possible to have...
By L.M. on 5 October, 2009 - 9:09 am -
It is possible to use master multiplexer.
For example:...
By dixinke on 5 October, 2009 - 12:34 am -
In the modbus network, there should no more than one master running at the same time....
By Lorne on 28 September, 2009 - 10:03 am -
Check out the PLC09 Arbitrator (www.calta.com). It was developed for exactly this application.
...
By Patrick L on 28 September, 2009 - 2:58 am -
Hi There,
HMS makes a gateway that is Modbus RTU slave to Modbus RTU slave. Connect one master...
Exception Coils, Diagnostic Register and Counters
New Replies:
By Harvard on 7 October, 2009 - 10:26 am -
All are device dependent. Modbus Registers are 16 bit register values that contain a binary value...
Question for anyone that uses Kepware OPC with a serial server.
New Replies:
By Fred Loveless on 7 October, 2009 - 10:16 am -
The advantage to do the protocol conversion (Modbus TCP to Modbus Serial) is that you can have...
By Jay Banks on 6 October, 2009 - 5:48 pm -
Thanks for the info.
Can you tell me if you have a preferred method to accomplish this, or does...
Read slave modbus from CPU Quantum.
New Replies:
By automatman on 7 October, 2009 - 2:29 am -
I've to read seven slaves.
I've considered your solution 3 and I think is good.
Now I'm...
By Schneider Italy on 5 October, 2009 - 10:24 am -
For sure M340 is a solution but is not cost effective!! You could use Premium HSBY instead of...
By automatman on 5 October, 2009 - 6:17 am -
I've asked to schneider spain and told me that CEV 174CEV30020 is out of catalogue. From schneider...
Hi there,
One way to solve it, could be to use a gateway from HMS, see:
...
By Schneider Italy on 4 October, 2009 - 4:03 am -
You have three solutions:
1. copy all 3x objects to 4x in the slaves
2. use CEV...
I too was confused by the original question. The issue is not with Modbus function codes but with...
By Bruce Durdle on 2 October, 2009 - 9:37 pm -
Going back to the original post, I think that the problem is that the scanning feature within the...
By Harvard on 2 October, 2009 - 5:17 pm -
I was mistaken about Function Code 6 because it writes single Holding Registers (4xxxx). Function...
By Harvard on 2 October, 2009 - 4:54 pm -
Not sure what you mean by "the company that originated Modbus protocol" but, Modbus by...
By automatman on 2 October, 2009 - 11:58 am -
Thank you for your interest.
I have questioned, but this configuration has two CPU's for...
You are correct. Unfortunately, the company that originated Modbus protocol did not elect to...
Problems communicating with an INFI-90 system over fiber media converters using serial SemAPI w/ PI interface. Communications drop constantly, points take forever to load.
New Replies:
By sd on 6 October, 2009 - 9:03 pm -
Try the converters by Transition Engineering.. So far so good with my Infi90 ;)...
I'm developing a HART modem and I have a problem with the network and Otxa HT2015 HART.
Write request to the RNI through the Matrikon OPC.
New Replies:
By Adriel Michaud on 6 October, 2009 - 6:11 pm -
Needs to be installed on the same computer as the RNI software. More information is available in...
By celticcc1 on 6 October, 2009 - 2:20 pm -
Hi,
When installing the RS3 RNI OPC server, does the RNI software be located on the same machine...
I need to connect to an HMI that does not have AS511 support...
New Replies:
You could use an AS511/TCP-IP port adapter like those from IBH - see...
Hi, can anybody help me please..? I need to do a connection Step 7 to Excel.
New Replies:
By SSV on 6 October, 2009 - 3:11 am -
If you have Siemens SCADA WinCC also in your application then you can use its inbuilt driver DDE...
from the "propriatery but widely publicized protocol". department...
Grundfos GENIBus specificationlooking for "programmers reference" for Grundfos GENIBus protocol. ...
New Replies:
By Zhenya4880 on 6 October, 2009 - 12:28 am -
There is description of GENIbus protocol in sources of picflow.
http://picflow.sourceforge.net/...
Control Center will change configuration or parameters of an IED via an RTU. Control Center has direct communication with the RTU but not with IED. RTU has direct communication with IED via IEC 61850 protocol.
Looking for a upper bound of prediction error with Kalman or RLS algorithm for a single input and single output.
If i send the command(010300210001, crc, crc) using serial port in VB.NET. I don't get any response.
New Replies:
The tutorial actually is great and should answer all you questions but just to add...
Point 2.) ...
> 1.) You have got to set up the port - Port Number, Baud rate, start/stop bits, data bit,...
Unfortunately you are a long way off the mark.
1.) You have got to set up the port - Port...
I am a newbie also, maybe you are closing the port before info or string is read. vb has examples...
We need to talk to Crestron with a Beckhoff PLC, by using the Crestron read/write blocks
An inquiry about programming cable and manuals for PCS 095 Operator Panel
Offshore hydrocarbon gas detectors' voting criteria
New Replies:
By Phil Corso on 29 September, 2009 - 1:00 pm -
Arvinon... An ESD company I once had provided M of N voting systems for applications similar to the...
By Aravindh on 29 September, 2009 - 6:36 am -
Hi,
May i know how did you manage this voting requirement? Kindly request you to share me your...
How from a VBScript can I talk to an AB PLC5 using a Wonderware DAS Server(DASABTCP)?
New Replies:
Thanks for your reply. I'll have a look on your suggestions....
Grass root project looking a cheap way of bringing groups of temperature signals that are in close proximity into a DCS
New Replies:
By David on 28 September, 2009 - 7:10 pm -
HART is an FSK signal superimposed onto a 4-20mA signal from a field transmitter. The HART signal...
>> groups of temperature signals <<
> I would think that you mean thermocouple...
DLL difference
New Replies:
LLC and MAC are not any relevant terms in ModBus domain.
I'm just guessing, but could you be...
I would like to see some sample code. where a micrologic 1100 is being used as a Modbus master.
New Replies:
By bob peterson on 28 September, 2009 - 2:02 pm -
I believe there is a knowledge base article on this topic....
INTERFACING SIEMENS S7 PLC WITH ABB AC800M + COMPACT HMI
STG Mark V simplex C processor gives up the ghost intermittently
New Replies:
The topic is very much interesting
We do have simplex Mark V system and we faced similar...
S7 313C-2DP set as a DP Slave but a Master also appears on the network at same node
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