from the Process Control department...Watlow F4 not being detected
Watlow F4D will communicate with one computer but is not detected on another.
> There's no option with the card to turn off the flow control, Isn't flow control done in...
from the Forum department...HART communication
HART multidrop limitation
The limitation is a HART 5 limitation, according to the HART Foundation's HART Communication...
from the Forum department...Modbus rtu over rs232, Master sending requests continuously
No mention of this possible scenario in specification.
The diagram on page 4 of the Modbus Application Protocol Specification V1.1b shows the client...
from the Forum department...Voltage drops in a 2 wire transmitter
Voltage drops to 5V after connecting the i/p terminal to the sensor. Sensor is basically a RI converter .
> 24v DC i/p is given from PLC I'm confused. An I/P should be connected to a PLC analog...
from the Forum department...IS Barrier Circuit
How to identify IS Barrier Circuit in a existing system?
The Whessoe 01146 spec sheet says ATEX approval: - Category: Ex II 2(1)G - Marking: EEx...
Intrinsic Safety is one approach to dealing with electrical apparatus in hazardous areas. ...
from the Instrumentation and Control department...HART Pass Through IO Cards
HART Pass Through IO Cards
One might assume that any HART enabled analog input card would be able to deal with the primary...
from the Anyway will do department...PLC Rack Layout
Project group wish to install a new rack above existing racks. Would like a standard to refer to for correct installation. Manufacture, though opposed, do not have written objection as it can be done.
In 30 years, I have never encountered a blind or illiterate PLC technician. If the techs at...
from the Forum department...Communicating using a RS-485 device to ASCII or Modbus
RS-485 can be set in eiher ASCII or Modbus mode
The manual says that the module defaults to Modbus RTU on power-up (pg 45). The mode can be...
from the New student department...Thermocouple compensation
How does compensation cable used with thermocouple, and can someone brief to me how does a smart transmitter compensate the unwanted voltage in thermocouple system?
The thermocouple law of intermediate metals says that junction terminal strips for thermocouples...
from the INSTRUMENT department...Hastelloy"C" material in 33% HCL
Seal diaphragm material HASTELLOY"C" IN 33% HCL service
A bulged out diaphragm is the condition that appears from hydrogen ion migration, when hydrogen...
from the automation department...Alpha Omega TEC controller series 800
Need help programming the Alpha Omega TEC controller series 800 using RS-232 (Modbus protocol)
Software and RS-232 in today's world means using a USB/RS-232 converter, unless you're using an...
from the level instrument department...Ultrasonic level transmitter on humid tank
level sensing value is fluctuating for ultrasonic level transmitter installed on the humid tank.
Moisture on the face of a transducer is a known problem with ultrasonics. The temperature of the...
from the software department...Modbus device discovery with many Slaves.
How do we handle device discovery/configuration of slave-ids with Modbus-RTU with multiple slave nodes (from different vendors) on a RS-485 bus ensuring no duplicate nodes.
> What do large EMS companies do when they have multiple devices from different companies to...
from the Forum department...Serial RS232 over Ethernet
What would you recommend for communicating with a serial RS232 based device over a local LAN network?
My memory of serial printers was that they needed flow control - small buffer memories and...
from the Loop Power department...Loop Powered device not turning on
Loop Powered device not turning on, V too low?
250 ohms is a low load value for an analog output. It only takes 5Vdc to drive 20mA through 250...
The Metso ND9000 spec says: Load voltage: up to 9.7 VDC/20 mA, (corresponding 485 ohms) So when...
from the Forum department...OPC via Modbus
Connect OPC via modbus.
>based on the FTDI chipset. I second the nomination of the FTDI chipset. Just today I...
>based on the FTDI chipset. I second the nomination of the FTDI chipset. Just today I...
from the Automation List department...Source / sinking problem
PLC analog sinking module and sensor is also sinking
Whoops, took a closer look. Correction to the diagram. Wiring should be 24Vdc (+) to Sensor...
Assuming that the symbols at the 24Vdc power supply are (+) and (-), what you drew is a classic...
from the Control valves department...Info on valve other than HART protocol
How can I change the parameters of Fisher Valves?
You don't say which positioner you have. Some positioners have keypads and a menu. But if you...
from the Arrgh, bloody gremlins department...problematic RTD displays
Five RTDs in use on three vessels. Display fine on two controllers, not on the others.
You should look up the part number on the relays that switch the RTD signal and make sure that the...
It isn't clear to me exactly what the problem, "all over the map" means (no examples...
from the Electrical Instruments department...OPC Server
Three Slave device sent data through modbus TCP or RS485 to OPC Server
OPC was originally promoted as an alternative to DDE, a Microsoft protocol for communicating with...
from the Forum department...Constant downstream pressure across HP valve
Constant downstream pressure across HP valve
Sounds like a conventional pressure regulator to me, with the inherent proportional droop in flow...
from the Design department...Condensate Pot for Pressure Transmitters
Hookup design of pressure transmitters for steam application.
The idea is to - have two condensate pots, one for each impulse leg, at exactly the same...
from the Forum department...Remotely process and pump control
Specifying a low pressure switch/transmitter to de-energize two upstream pumps.
Electromechanical pressure switches need no power to operate, the line pressure on the sensor...
from the Forum department...Books on distributed control system
Looking for books on distributed control systems
Practical Distributed Control Systems (DCS) for Engineers and Technicians IDC Technologies. - 569...
from the Utilities department...What is the best level transmitter for my application?
Looking for a level transmitter to replace a wrongly located bubble tube level system.
correction - gallon of water weighs 8.34 pounds...
What about re-locating the bubble tube? $10 of plastic pipe . . . Did you correct for...
from the Forum department...Modbus TCP
Transfer Data using Modbus
>1) How to Transfer the Data from Slave Device to other Slave device using Modbus TCP? A...
from the Forum department...Establishing & managing redundancy of Potential Free contacts
Establishing Redundancy of Potential Free contacts as inputs
potential free contacts Contacts can be potential free in a standalone device, but for any means...
from the Forum department...Application of Analog Communication in Process Industry
Analog communications in present day automation sector
The analog signal, 4-20mA, is used worldwide because - it is simple and rugged - in its 2...
from the Automation List department...First Impressions: Koyo Click
Using an inexpensive PLC for an automation contract job
Thanks for the excellent review. I'm going to get one just to try it out....
from the Forum department...Isolating a 4-20ma signal
Isolating a 4-20ma signal coming from a UV lamp unit
The loop powered isolators I'm familiar with scavenge power from the loop power supply (on the...
from the meter department...Flow Meter continues to register after shutoff
Our flow meter continues to register and record flow when all pumps are off....why? How?
Either there's a delta P and flow path so the meter is indicating true flow or there's true zero...
from the Technical department...Relay Contact
Convert +5V digital output to dry contact output
Ans: No. The solution Mr. Myres recommends is exactly what the alarm input board spec calls for -...
from the Forum department...hysteresis setting for master input
PIC controller, getting set point from PI with hysteresis setting of .1 psi.
If you're a newbie and you're using the word 'hysteresis', you must have picked it up from...
from the INSTRUMENTATION department...HART Communicator values
what is happening in the transmitter when connecting HART communicator in the loop and feeding 25% or any values
If you connect a HART communicator to a HART transmitter in a point-to-point current loop, the...
from the sig department...Limited register response using hitachi x200.
Limited registers using hitachi x200.
Unitronics issue with comm retries? RS-485 reflections from cabling's impedance mismatch? I...
from the Forum department...SCADA sample project - Educational/Training
I need a sample project in the field of SCADA for training purposes.
Sometimes you gotta bite the bullet and buy the book and you find out it pays for itself 20x over...
from the Instrumentation department...Hook up of DP type flow meter
Is it possible to install a DP type flow meter above a liquid (Cooling Water) line?
Do not locate the high and low side taps/ports at the 'top' of the pipe; do not locate them at...
from the Water flow meters / water valves department...Searching for automatic water valves hardware
Second course student on internship seeks help.
Valves are machined chunks of metal or plastic that don't talk Modbus. But the positioner or...
from the Calibration department...Configuring Foundation Fieldbus Transmitters
I had a problem while configuring the Foundation Fieldbus Transmitters kindly provide solution for the same
I could not enable a channel on an ISA100 wireless field transmitter until I had put the device...
from the Ge fanuc PLC department...GE Rx3i PLC system and Motorized Valve
Is GE Rx3i PLC system able to operate Motorized Valve
I know a number of controls guys who have programmed a PLC to run a motorized valve, but there are...
from the instrumentation department...flame detection principal
i dont understand how flame detection is happening in flame detector 45UV5 1010 model and digital signal is being sent to plc for tripping purpose.
The principles of operation for Fireye's UV flame scanner are explained in the opening paragraph: ...
from the Forum department...Siemens Hydroranger problem
4-20mA outputs keep going out on Siemens Hydroranger
Siemens has a single channel ultrasonic level unit, the LUT400, which I saw a month or two ago. ...
from the Modbus, Wireless Networking department...Problems reading Modbus input registers
Trying to read modbus input registers from a WirelessHART gateway. getting fixed values at all input register addresses when they are mapped to varying sensors.
The first thing that comes to mind when you write, "When I try to poll input registers"...
from the Forum department...HP MEG filtration DP Tx Selection
DP transmitter selection for HP MEG filtration
1) A datum is missing - what is the expected DP range? It's a filter application, but is the...
The light at the end of the tunnel is the headlight of an approaching