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Control.com member...
Member Information and Posts by Harvard
from the Control department...
Modbus protocol, HVAC system control
Topic: Communications systems and equipment.
Originally posted by JD on 13 August, 2009 - 1:14 pm
Return strings from Modbus simulator application differ from that of HVAC system harware
New Replies:
It is not unusual to have byte reversal issues. One of the devices, Host or Slave, should have a...
from the Forum department...
Convert SIMATIC to MODBUS address
Topic: PLCs and related questions.
Originally posted by martin on 12 August, 2009 - 1:02 pm
Convert SIMATIC to MODBUS address
New Replies:
To poll Address 11, Reg 40001 for 2 Regs: 0B 03 00 00 00 02 C4 A1 To poll Address 12 register...
from the Forum department...
Modbus frame size
Topic: Communications systems and equipment.
Originally posted by Bin on 6 August, 2009 - 5:25 am
Can I use the Modbus frame size larger than 256 bytes?
New Replies:
No! If you notice in the Function Code 3 slave response the 3rd byte is the byte count of the data...
from the Forum department...
MODBUS and flow meter
Topic: Software, including programming, OS issues, etc.
Originally posted by zabee on 29 July, 2009 - 1:26 am
how a flow meter communicate
New Replies:
I think you are saying you need to convert pulses from the flow meter to an accumulator that...
from the RS-485 department...
Modbus ASCII RS-485
Topic: Communications systems and equipment.
Originally posted by Vinod Gavande on 29 July, 2009 - 1:32 am
How many slave devices cab be multidroped on RS-485 bus?
New Replies:
The Master is just another device, so 32 including the Master is your correct answer. Remember, the...
from the Design department...
Modbus RTU protocol format with ODD PARITY
Topic: Communications systems and equipment.
Originally posted by vijeta on 1 July, 2009 - 1:45 am
What is the MODBUS RTU PROTOCOL format for ODD PARITY?
New Replies:
Parity is redundant and never normally used WHEN CRC error checking is implemented. Parity is not...
from the Forum department...
Software simulator as Modbus device
Topic: Communications systems and equipment.
Originally posted by dan on 16 June, 2009 - 6:29 pm
Modbus adaptor
New Replies:
I think you are asking for a ModBus Slave Simulation application that will respond to any ModBus...
from the Automation & Control department...
MODBUS Analog Input
Topic: Local and wide area networking in factory automation.
Originally posted by Tashar on 9 June, 2009 - 12:41 am
Does a MODBUS AI (MAI) make sense??
New Replies:
Modbus has Holding Registers and Input Registers. You cannot write to a Input Register, it is for...
from the Networking department...
Modbus RTU Passive Taps
Topic: Local and wide area networking in factory automation.
Originally posted by Shawn H on 29 May, 2009 - 11:55 am
How long can the taps on a modbus network be and are you limited to the amount of taps for 32 devices?
New Replies:
RS485 2 wire 1/2 duplex cannot have any "Tap length". There are only 2 ends to an RS485...
from the Forum department...
micrologix 1400 and modbus rtu woes.
Topic: Communications systems and equipment.
Originally posted by blackj on 19 May, 2009 - 4:26 pm
a question about modbus function codes, as well as looking for help with micrologix1400
New Replies:
Modicon Register 40001 is Modbus Register 0. The correct poll is: 01 03 00 00 00 02 C4 0B ...
from the Can't talk to SATEC meter department...
MODBUS Communications Tester
Topic: Communications systems and equipment.
Originally posted by Thomas Toms on 27 April, 2009 - 2:52 pm
PLC Modbus Master will not talk to SATEC power measurement meter.
New Replies:
I have a freeware Win32 Console application that will monitor two RS232 1/2 duplex data streams...
from the Different versions of Modbus? department...
Modbus RTU on ABB AC250
Topic: PLCs and related questions.
Originally posted by Laban on 2 April, 2009 - 8:11 am
Are there different dialects of Modbus?
New Replies:
While there are variations I have never seen something as you describe. Here are two write...
from the Forum department...
Do you recognize this error checking?
Topic: Software, including programming, OS issues, etc.
Posted by Harvard on 31 March, 2009 - 11:23 am
Do you recognize this error checking?
from the Forum department...
connect multiple devices to RS-232
Topic: PLCs and related questions.
Originally posted by Abhijeet on 26 March, 2009 - 6:55 am
connecting multiple devices to modbus over rs-232 by using RS-232 to RS-485 converter
New Replies:
According to the Gould Modbus Protocol Reference Guide PI:MBUS-300 Rev B, a Function Code 7 has a 4...
Topic: Communications systems and equipment.
Originally posted by Mikey on 19 March, 2009 - 8:51 pm
modbus analyzing from the outside
New Replies:
Most likely caused by timing settings. I would verify the Slave "Turnaround Time" setting...
Topic: Local and wide area networking in factory automation.
Originally posted by ASh on 16 February, 2009 - 6:36 am
Problem connecting 2-wire modbus RS-485 to 3-wire Modbus RS-485 on daisychain modbus network.
New Replies:
Start with the MOXA 3180 and add one slave at a time. Do not be suprised if the Data+ and Data-...
Topic: Engineering and workplace issues.
Originally posted by Timothy Burgess on 5 February, 2009 - 3:26 pm
Problems talking to a slave machine using the Modbus RTU protocol.
New Replies:
You will not get a response from a Modbus slave if the CRC is in error, it will be assumed to be...
Topic: Communications systems and equipment.
Originally posted by interop on 3 February, 2009 - 12:04 pm
Can only read 6 registers from Controlotron 1010 flow meter via Modbus
New Replies:
If this connection is Modbus RTU protocol then you would not want to be using parity and 7 bits....
from the Help with modbus RTU department...
Elpro 905u G / Adams 5000
Topic: Communications systems and equipment.
Originally posted by Adam Rayner on 1 February, 2009 - 12:03 am
Trying to read Reg 400001 from a Adams 5000E to a elpro 905u-G
New Replies:
>So should i set the radio to read register 40001 or just 0?< Probably 40001 and it will...
Modicon Register 400001 is a misprint, should be Modicon Register 40001 which is polled as ModBus...
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