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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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Posts from...
Today, Thursday, November 20, 2008
Just wondering if there are lower cost alternatives out there to this 1024 step encoder.
New Replies:
By Steve Myres on 20 November, 2008 - 2:08 am -
By Steve Myres on 20 November, 2008 - 2:08 am -
Encoder Products sells good encoders for pretty cheap. Or you could try AutomationDirect.com...
3 Phase motor rotation
New Replies:
By Curt Wuollet on 20 November, 2008 - 1:00 am -
By Curt Wuollet on 20 November, 2008 - 1:00 am -
In any VFD for that matter, the line simply powers a rectifier. Unless the drive manufacturer...
By Steve Myres on 20 November, 2008 - 12:13 am - Or if speed control would be of any value in your application, you'll get this intrinsically in a...
By George Younkin on 19 November, 2008 - 10:08 pm - Three phase motor rotation can be done by reversing any two of the three wires. What you want to do...
By William Hinton on 19 November, 2008 - 8:08 pm - Bruce,
Motors powered from a variable frequency drive go the same way even with the input wires...
By Roy Matson on 19 November, 2008 - 11:09 am - 1. If you were operating your motors on a VFD, they would always go the same way as the AC is...
By William Sturm on 19 November, 2008 - 9:00 am - I suspect the answer is in the VF drive. Are you using a VF drive or a contactor to run the...
By Phil Corso on 19 November, 2008 - 7:44 am - Responding to Bruce's 18-Nov-08 (15:17) query... the circuit you seek is used all over the world:
...
By Zacharia, Tomy on 19 November, 2008 - 2:14 am - A phase sequence relay/device which can indicate correct phase sequence and two contactors would be...
Is there anyone out there that might know anything about the Active Control Inc. serial comms protocol used by Carter wind turbines?
New Replies:
By John B. on 19 November, 2008 - 11:43 pm -
By John B. on 19 November, 2008 - 11:43 pm -
If anyone has any luck finding a solution for the CWT300 communication interface I would like to...
By Darran P on 6 November, 2008 - 5:51 pm - Only just found this response... the turbine is in the UK.
The current owner wants to get the...
When should I use a MCB and when a glass fuse for a control system?
I need a Cicode function that will export filtered alarm summary details to a file. I am using V6.1.
Control EtherNet/IP devices from a host PC
Is it advisable to use a barrier when using a RTD with EExd certification?
New Replies:
By Bryce Gillan on 19 November, 2008 - 6:20 pm -
By Bryce Gillan on 19 November, 2008 - 6:20 pm -
The RTD can be classed as simple apparatus and therefore the device does not need IS certification....
By Dick Caro on 19 November, 2008 - 2:11 pm - As I understand it, the IS barrier exists to block high current/voltages from entering the low...
By Roy Matson on 19 November, 2008 - 11:49 am - We install many instruments EExd in Class 1 Div 2 without barriers. For Class 1 Div 1
CEC 18-100...
By Bruce Durdle on 19 November, 2008 - 1:16 am - If the RTD has Ex d certification, you have two choices.
You can use it in a system wired to Ex...
I'm tryinb to connect 2 kinds of PLCs: SIEMENS S700 and TAC XENTA 913 with a FUJI POD UG430 trough a MOdbus.
New Replies:
By Ronny Wangssbro on 19 November, 2008 - 5:52 pm -
By Ronny Wangssbro on 19 November, 2008 - 5:52 pm -
TAC Xenta 913 is a Modbus/LON/BACNET gateway....
Reverse power trip
New Replies:
By Phil Corso on 19 November, 2008 - 5:33 pm -
By Phil Corso on 19 November, 2008 - 5:33 pm -
What has your instrumentation revealed?
Phil Corso (cepsicon@aol.com)...
By TilakGhoshal on 19 November, 2008 - 9:25 am - I suggest first of all have the governor of the 3rd DG checked for proper operation as well as the...
By Topak_Khan on 19 November, 2008 - 5:54 am - 1 - Is reverse power indicator separate from trip system? Is it calibrated?
2 - Is there a...
Converting Simatic TI-505 based on Simatic APT programming tools to Allen-Bradley Controllogix...
New Replies:
By Allard Gilles on 19 November, 2008 - 5:10 pm -
By Allard Gilles on 19 November, 2008 - 5:10 pm -
APT is object-oriented. Every data item (even a simple boolean) has a .status attribute. In basic...
By aan - on 18 November, 2008 - 12:24 pm - Dear Forum,
Thanks for your response Gilles.
Actually what I can't understand is: variable...
By Gilles Allard on 17 November, 2008 - 2:41 pm - > if (SS_S430=E.FAILED_SS or SS_S430=E.HELD_SS) and not(CYC_INT)
> then...
Looking for assistance with troubleshooting a fiber optic MB+ network problem.
Once again, we have a great unit that is obsolete. I am hoping someone knows of a good field mountable wide temperature range single loop controller that can be polled via RS485 or HART.
New Replies:
By Jeff England on 19 November, 2008 - 3:52 pm -
By Jeff England on 19 November, 2008 - 3:52 pm -
The heater is for extreme low temperatures (at least those we frequently see below 32 Deg F). Most...
By Roy Matson on 18 November, 2008 - 4:45 pm - I'm not sure why you are putting a heater in the enclosure. If it's NEMA 4 there should be no...
By Jeff England on 17 November, 2008 - 8:03 am - "Avoid the ethernet Modbus, it has problems."
That kind of made me chuckle. I have...
By Steve Myres on 16 November, 2008 - 1:41 pm - If that unit is otherwise suitable, could you maybe add a 5W resistor or something behind the...
By Carl Ellis on 15 November, 2008 - 11:04 am - For clarification: the NEMA 4 rating for the UDC is for the bezel/faceplate being sealed to NEMA 4...
By Roy Matson on 14 November, 2008 - 7:18 pm - I will go with Carl Ellis on this one, the Honeywell UDC is NEMA 4 when mounted in a NEMA 4...
By Jeff England on 14 November, 2008 - 10:17 am - The temperature operating range we are seeking goes from -10 Deg F to 120 Deg F as we see that...
By Carl Ellis on 14 November, 2008 - 12:50 am - Honeywell 1/4 DIN UDC controllers are NEMA 4 rated. It isn't clear what you mean by wide...
My boss wants to build a workbench to test the invulnerability of a simple SCADA system against hacker attacks.
Network startup delayed with WinCC 6.2
Which are your most favorite field instruments?
New Replies:
By mahesh on 19 November, 2008 - 12:56 pm -
By mahesh on 19 November, 2008 - 12:56 pm -
I love mercury filled level switches, where mercury is filled in a small rectangle type container...
By ultima on 18 November, 2008 - 10:50 pm - My favourite field instrument devices are (skip my latest post):
1. Differential pressure...
By Roy Matson on 18 November, 2008 - 12:02 am - In my experience the best flowmeter for slurry is a rubber lined Mag Flowmeter. Mining slurry is...
By Dooley, Vince on 17 November, 2008 - 11:34 pm - I work in the alumina industry and I am aware of many trials of ultrasonic flow meters over a 20+...
By Carl Ellis on 17 November, 2008 - 9:19 pm - Favorite Field instrument:
1) Plain old thermocouple, for its simplicity and durability.
2) ...
By Ultima on 16 November, 2008 - 9:05 pm - Hello,
I don't know about you guys but it seems that ultrasonic flow measurement still can't...
By Roy Matson on 16 November, 2008 - 1:33 am - Walt,
We have all seen the fancy pictures of a sound wave going through the pipe wall and bouncing...
By Roy Matson on 16 November, 2008 - 1:23 am - Bob,
I worked in the mining industry for many years. It is common practice for the grinding mill...
By Walt on 15 November, 2008 - 10:07 am - The doppler flow meter has a VERY restricted application set, but the vendors tend to oversell them...
By Bob Peterson on 15 November, 2008 - 9:52 am - The paddle type flow switches work pretty well in clean, non-visocus fluids. If misapplied nothing...
By Roy Matson on 14 November, 2008 - 10:44 am - It seems folks are reluctant to respond so I will start with a couple I hate.
Doppler Ultrasonic...
Is there a way to send device info over ModBus?
New Replies:
By Bob on 19 November, 2008 - 12:46 pm -
By Bob on 19 November, 2008 - 12:46 pm -
You can send a device name or other string over Modbus using a block of registers. Each 16 bit...
By BasicPoke on 19 November, 2008 - 10:13 am - I found the Report Slave ID (17) function, which I think will work for me, but I have a couple of...
By Don Lupo on 19 November, 2008 - 7:34 am - If the slave devices support the "Report Slave ID command -17 (11H)"
then that is a...
By Friedrich Haase on 19 November, 2008 - 3:10 am - Moin BasicPoke,
moin all,
MODBUS Application Protocol Specification V1.1a / June 2004
...
Micrologix 1100 <-> Lookout Protocol Drivers v4.5 <-> Labview v7.0
New Replies:
By David Wisti on 19 November, 2008 - 12:05 pm -
By David Wisti on 19 November, 2008 - 12:05 pm -
From what I understand the MicroLogix 1100 controller implements only one subset of the EtherNet/IP...
By frenchy on 18 November, 2008 - 2:40 pm - Adriel,
Thank you for your response!! Indeed I have spoken with NI. They were very adamant...
By Carl Burgess on 18 November, 2008 - 8:47 am - I've never done OPC to a MicroLogix 1100, but I have recently used a MicroLogix 1100 in a project.
...
By Bob Peterson on 18 November, 2008 - 8:02 am - Chances are pretty good that either the ML1500 of SLC500 setting might work. Or NI might have an...
By Adriel Michaud on 17 November, 2008 - 1:36 pm - Have you spoken with NI on the issue, and if so, what did they say about support for ML1100s? OPC...
from the Lost in RSLogix... department...
How Do I Hold the Output States When Downloading to an RSLogix 5000 PLC?How painful will it be to have to remember to reset the Program Mode state of each output to Hold Last State each time you download to the PLC and then back to Safe State?
New Replies:
By Roy Matson on 19 November, 2008 - 12:01 pm -
By Roy Matson on 19 November, 2008 - 12:01 pm -
Don't feel bad, I have been working with PLCs since early 80s. I was very surprised when I saved my...
Level Instrumentation
New Replies:
By Roy Matson on 19 November, 2008 - 10:56 am -
By Roy Matson on 19 November, 2008 - 10:56 am -
No, if the column of fluid is 1/2" or several feet in diameter the pressure is the same. I...
By ultima on 18 November, 2008 - 10:32 pm - Thank you, roy, but what if the volume of the containers, e.g. an open or closed tank, are...
By Juan Pinzon on 18 November, 2008 - 10:28 am - Friend,
I don't understand well your question but here is the following:
Hydrostatic pressure...
By Roy Matson on 17 November, 2008 - 11:56 pm - I think you have the wrong formula, Area has nothing to do with the pressure
P = SG * Height
A...
By ultima on 16 November, 2008 - 9:17 pm - Hello,
I need help. I am confused about how you determined the correlation between the P=F/A...
By Riolyn on 3 November, 2008 - 2:41 pm - So it's just a good engineering practice but is not mentioned in any Standard. I thought there...
By Roy Matson on 31 October, 2008 - 8:11 pm - No, there is no standard, it depends on the site.
If it's a critical application it might have...
By wboyes on 31 October, 2008 - 10:49 am - I don't believe that there is a standard, but it is good engineering practice if the level in the...
By Sourav on 31 October, 2008 - 5:40 am - Yes, it is required to install a level gauge with level transmitter. The level gauge is for local...
How do I compute knee-point voltage of CTs for transformer Differential and Restricted earth fault protections?
What does this signal name indicate in MK V - L51BT1 & L51BT2?
New Replies:
By DAMENE Amar on 19 November, 2008 - 8:59 am -
By DAMENE Amar on 19 November, 2008 - 8:59 am -
Hi,
In Mark V this signal name indicates:
L51BT1 - the breaker for the 88BT1 motor of fan1 On...
By CSA on 16 November, 2008 - 7:47 pm - I think there's some kind of typographical error. Stranger things have been known to happen, but...
By Mambo on 16 November, 2008 - 1:31 pm - Hello,
FYI, 51 - stands for AC Time over current relay.
Relay that functions when AC inputs...
Using tags in WinCC in Visual Basic
Communication of two MARKV Cabinet with a single <I>
Develop and implement Modbus/TCP protocol using C.
What considerations to deal with when connecting instruments to PLC?
New Replies:
By Patrick on 19 November, 2008 - 5:56 am -
By Patrick on 19 November, 2008 - 5:56 am -
Hi there,
It depends on what fieldbus the PLC is using and what baud rate. If you know what...
By Vinod Kumar KG on 19 November, 2008 - 1:31 am - Be more specific when you ask questions to get precise answers.
If you are hard-wiring, the...
How can I achieve the required accuracy?
how is it decided which temperature to select?
New Replies:
By Zacharia, Tomy on 19 November, 2008 - 2:16 am -
By Zacharia, Tomy on 19 November, 2008 - 2:16 am -
With aircraft engines, if the duty is extreme, say on afterburner, then the clock ticks faster and...
By n_ln on 18 November, 2008 - 1:16 pm - Hi,
Equivalent Operating Hours (EOH) is the term used in ALTOM, ABB gas turbines. It is not the...
By hall on 15 November, 2008 - 10:03 am - Hi,
I understand that equivalent operating hours are the time period between inspections...am I...
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