Posts from...Today, Wednesday, April 16, 2014
from the Forum department...MODBUS Break Condition & Checksum
MODBUS RTU using RS485 to RS232 converter connected to RS232 to USB converter to communicate with electric meter using MODBUS Poll.
By Steve Myres on 16 April, 2014 - 1:04 pm -
Maybe try a different converter (or your current setup with another slave). FTDI sells some that...
from the Communications department...OPC server communicate with OPC server
How do one OPC server share data with another OPC server?
In order to facilitate such communication you typically use an OPC client that connects to both...
from the Forum department...Instrumentation cables sizing
Instrumentation cables sizing
By Franco Kew on 16 April, 2014 - 6:03 am -
Dear Ahmed Sami, Your question is incomplete I can say. Cable cross section and hazardous area...
Ahmed Sami, Choosing wire/cable for a particular application is a very involved process. Does...
Why do you sugget 1.5 mm2 cable? Does that follow any standards recommendation or calculations? ...
from the Salse Department department...GPRS data transmission
Using GPRS modem to send data from PLC to OPC server on a PC with SCADA.
do you have a static IP address for PLCs? Alex. Contact me. Skype: skype_redfox...
from the Computer department...Serial Communication VB Code
Continuous reading of serial input
from the Forum department...Vijeo Citect ModBus RTU Write Problem
Vijeo Citect ModBus RTU Write Problem
> Anyone got the solution? try without tagwrite tagname = ArgValue1...
By Joelle on 14 April, 2014 - 12:56 pm -
Hello, I have the same problem. > I'm facing a problem in sending data to a Modbus RTU...
from the Automation and EMS department...Modbus Data transmission time
How to calculate time to receive data from slave to master in daisy chain connection of slaves, if my slaves are 20 and single master.
By Patrick Lansdorf on 16 April, 2014 - 1:55 am -
Hi, I have made a simple Excel sheet, where one can calculate the line time. You will need to...
By Steve Myres on 15 April, 2014 - 12:55 pm -
Slick idea on the prefetch! ...
By Lynn August Linse on 15 April, 2014 - 9:31 am -
>> What's a rule-of-thumb value for >> RTU-TCP latency in a Digi Modbus bridge...
By Bhadresh Sarvaiya on 15 April, 2014 - 1:29 am -
> Mr. Linse, > What's a rule-of-thumb value for RTU-TCP latency in a Digi Modbus bridge...
Mr. Linse, What's a rule-of-thumb value for RTU-TCP latency in a Digi Modbus bridge product? ...
By Lynn August Linse on 14 April, 2014 - 10:36 am -
Just be careful to accommodate the delay-back off during failure. With a single device, it might...
By Curt Wuollet on 13 April, 2014 - 5:19 pm -
It depends on how it's written. In the system I just set up, I use a state machine to do the...
By Bhadresh Sarvaiya on 13 April, 2014 - 5:14 am -
Thank you for your kind reply.. but i didn't get answer as i want.. i didn't understand your...
You know - the word size, 11 bits - the number of words in the master message - silent...
from the Forum department...SCADA RTU in Substation
Why use SCADA RTU in a substation? What is the purpose of SCADA RTU?
from the INSTRUMENTATION department...UREA FLOW METER
What type of flowmeter can be installed in a Urea duct as a source of FD and ID fan in the duct?
By Billy on 15 April, 2014 - 10:30 pm -
What are you measuring? Just air flow? We use a DP transmitter for our prill tower air ducts....
from the Which HMI do you simply Love or Hate? department...TOP 10 list of Best and Worst HMI & SCADA
I know everyone has their personal preferences, but I think it would be more interesting to discover which software is the Best or worst...
By Devin Montcrief on 15 April, 2014 - 12:28 pm -
> WinTr is advanced SCADA SOFTWARE for monitoring and saving data of manufacturing processes...
from the Level Control department...Magnetorestrictive Level Transmitter issues
Extreme vibration and loss of signal on level transmitters
By Sam on 15 April, 2014 - 8:12 am -
Hi Mateus, there is only one instrument when you are working offshore on a FPSO or Platform...
from the Power Electronic Engineering department...Medium Voltage Drive Variable Frequency Drive
Application of Medium Voltage Drive in industry to save energy, obtained desired output
from the I'm in trouble department...MODBUS ABB ACS550 Connection trouble
MODBUS connection trouble... How to create a virtual COMM port
By MC on 14 April, 2014 - 6:39 pm -
Looks like USB conversion would be your best alternative. Here's a device from a company that...
By Steve Myres on 13 April, 2014 - 11:26 am -
The port behind the keypad, although RJ45, is serial, not Ethernet, so even if you could find a...
from the Urgent department...Time and Date in Honeywell control builder
How could use time and date in control module?
thank you so much sir but unfortunately i couldn't find variables CEE1.HOUR...... i have many...
from the Thermocouple department...Thermocouple cable configuration
Choosing thermocouple cable configuration- twisted pair or coaxial (multi cored)
By rvsaradhi on 14 April, 2014 - 11:59 am -
please note that T/C TYPE N lower cost compensated can be used depends up on your critical...
By W.L. Mostia on 14 April, 2014 - 11:42 am -
It is seldom ever a good idea to run un-twisted pair thermocouple extension wire. Thermocouple...
Shrk, www.omega.com is a very good resource for all kinds of sensors, particularly RTDs and...
By Shrk on 14 April, 2014 - 4:53 am -
Hi. Thanks. tried looking, did not get much info. Will certainly try again. Again, thanks...
from the Forum department...Windmill Alternator
Control of windmill alternator load
Karsten Rasmussen... following are two ways to change speed: o control blade-pitch. o control...
Karsten Rasmussen, I think it's going to be pretty difficult to control the speed of a wind mill...
from the Forum department...8-bit data types in Modbus registers
Are 8-bit data types obsolete for Modbus?
By Lynn August Linse on 14 April, 2014 - 10:39 am -
A bit of historical trivia... Modbus never had 8-bit data types. The original PLC were made back in...
> Since registers are always 16 bits, does it even make sense to provide data types of 8 bits...
from the Forum department...Actuator indication and control
How to obtain indication and control from a Rotork actuator
Other types of actuators use two drive signals: - one signal drives the actuator 'open' - the...
from the Engineering department...Siemens marshaling wire
Brand name of Siemens' 0.5mm thick marshaling wire
from the Forum department...Clarification about droop and frequency control
Turbo-generator response to changes in the power grid frequency.
Dear All, I am working on Hitachi Gas Turbines and Shin Nippon Steam turbines. There are three...
from the Tag Prefix WinCC V7.2 department...Tag Prefix WinCC V7.2
Communicating with Tag Prefix WinCC V7.2 using MODBUS TCP/IP protocol.
from the ABB Advant department...ABB OS500 upgrade
ABB OS500 upgrade to newer version HP B2600
By Will P. on 13 April, 2014 - 9:13 pm -
Thanks All for your replies....
from the Forum department...Effect of improper grid connection on reactive power
Increase in reactive power drawl at generation source.
Neo, I have read and re-read this post several times the past couple of days--mostly hoping...
from the Annoying Exceptions department...Negative Acknowledge and Bad Karma
How do you feel about security exceptions not being, you know, informative?
By JulieInAustin on 13 April, 2014 - 2:24 pm -
> What product are you working on, and are there any other security enhancements you are making?...
By JulieInAustin on 13 April, 2014 - 2:16 pm -
> Wait....when Digi hires you, you'll STOP writing code?? Digi -- don't hire Julie! No, Digi...
from the Automation department...DCS Yokogawa Communication Issue
Yokogawa DCS communication with Modbus slave device using ethernet redundant connection with ALE111.
from the Maintenance department...Mark V TMR servo commands
Difference in servo command in TMR panel for second stage nozzle
Brian, When did this problem start? After a servo-valve was replaced? This is not a simple...
from the Forum department...Connecting Floboss 107 to DeltaV
Student with a project to connect a Floboss 107 to DeltaV for an HMI.
An analog output can't very well handle a totalizer value because of the lack of dynamic range on a...
from the Forum department...Condensate pots and flow measurement
Using condensate pots for flow measurements
1. The purpose of condensate pots in steam flow measurement is to isolate or seal the transmitter...
from the Automation List department...Interfacing VFD with PLC
How to interface variable frequency drives with PLCs?
By N.A. on 12 April, 2014 - 5:02 am -
If You Want only on/off control from PLC, then connect the drive to digital output module. and if...
I know it all. I just can't remember it all at once.