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Hi, I would like to provide the PLC control for a scenario where the temperature in a machine, heated by the two electric heaters, is controlled with use of 1 TCK and 2 s/s relays. Please see draft “plc4” sent attach. The TCK is fixed to the machine and is not in a physical contact with the heaters. Nominal temperature of machine is 200degC. The machine temperature tolerance is +/-2degC. This means that the heaters should be turned on when machine T drops to 198degC and turned off when T reaches 202degC.  For this moment I have created the start PLC diagram outlined on draft “PLC4”.  I am still learning PLC. Therefore, I would be very grateful for your opinion whether the PLC diagram shown on picture “PLC4”, in terms of the tools used (direct contact, direct coil, etc.) and their layout, is of proper design. I know that there is much more work needed to complete this task (e.g. set up of the variables, etc.). I am using Unilogic software. Please help. Regards

Hello, I need to make an ethernet communication Siemens S7-300 <> Omron G9SP. The HW of the Siemens that i us are CPU 315 2DP and CP 343-1 Lean. I did try to follow the Omron manuals Z922 and Z924, but faced with some problems. First of all in Z924 there is no complete HW configuration of Siemens (communication configuration is missing). Also, formats of messages differ in both manuals. Maybe there is an Simatic Step 7 project example, that i could open with Simatic Step 7 manager to do a deeper investigation, or maybe somebody has a lot more experience in this case? Thank you in advance.   WBR @rturas

Hi everyone.  Is it possible use mitsubishi safety plc as logic solver for fire and gas detection system  on the plant ? 

Hi All, We have an old machine using a Mitsubishi Fxo-30MR/ES and I will be replacing the PLC with a FX3S-30MR/ES.  This old machine would power some led's on a panel mounted PCB using the PLC outputs.  The 24V from the PLC output would go to the PCB board where a resistor would drop the voltage for the LED.   This PCB is damaged I would like to avoid getting a new PCB made and instead power some panel mounted LED rated for 24V directly form the PLC output.  I guess these panel mounted LED have a built-in resistor.  Power consumption for the LEDs are 20mA at 24V volts.  The 24V power supply has plenty of capacity for this. Are there any issues with doing this? I have attached the spec sheet for the panel mounted LED (I will be using the 24V versions).   Panel Mounted LED.pdf

Good day, We are using Guardlogix 1756-72s controllers for our ESD system. We created safety add-on instruction in RSLogix5000 v20 and wanted to test it using RSLogix Emulate 5000, however we are getting an error that safety add-on instructions are not supported in standard controllers. Is there a way to test safety code using Emualate or Softlogix?

Which type of electrical panel is most reliable, give some idea about that ..?

Hello. I tried to read/write from/to safety cpu (QS001) over MC protocol. I managed to read from cpu devices but i couldn't write to any safety cpu device. It was possible to write data to Q series plc (Q02HCPU in my example) with MC protocol. I am searching any method of writing to safety cpu (QS001). If anyone could this before? And are there any settings in GX Developer (GX works) for access to writing to QSCPU? P.S: As known it's possible to read/write from/to Q series PLC with MX Component. It's also available reading from QSCPU with MX component. But cannot write to safety cpu with MX component (written in Mx component manual). Thanks.

Hello, I have a remote io cabinet with a rack of Siemens ET200isp. This was chosen because the almost all of the equipment connected to it comes from the hazardous area and is Ex ia. This presents me with a problem because I have two pumps that I need to turn on and off with this rack, and I cannot drive a contactor with intrinsically safe io for 2 reasons: 1. The power output is too low to pull in a contactor 2. There would be no barrier to separate the intrinsically safe wiring from the 'safe area' wiring containing the 3 phase for the motors. Output card is a 4 F-DO Ex 17.4V/40mA (6ES7138-7FD00-0AB0) My original plan was to use a Pepper and Fuchs KFD2-SR2_Ex2.W on the output of the Siemens DO card to provide a safe area dry contact that I can use to power my contactor. This did not work however as the KFD2-SR2 is not designed to be connected to an active current source, so both the IO card and the barrier were trying to power eachother and switching was not possible. I can get it to work if i power a standard 24v relay from the DO card, however this does not solve the problem of properly isolating the hazardous area wiring from the safe area wiring as a relay is not an intrinsically safe barrier. I can put a zener barrier in line with the coil of the relay however this cuts the power down too much and the relay contacts do not reliably pull in. I'm asking if anyone has any ideas, we are beyond the point where installing a new IO rack that is non-ia is an option, it would require a whole new cable run for the profibus. Is there such a thing as a relay that can be powered by the intrinsically safe output? I hope that is enough detail, please feel free to ask if more info is required. Thanks in advance for any suggestions.

I was hoping to get feed back on my website.  The site is for beginner PLC programers. The tutorials start right from the beginning with describing what a PLC is and then teaches basic instructions. Please take a look and tell me what you think, I would love the feedback.   thank you   ladiesandtech.com   1. What is a PLC Part1  https://ladiesandtech.com/2015/12/03/watch-whatisaplc1st-on-youtube/  2. What is a PLC Part2  https://ladiesandtech.com/2015/12/09/watch-what-is-a-plc-part-2-on-youtube/ 3. What is a PLC Part3 https://ladiesandtech.com/2015/12/15/watch-plc-programming-tutorial-for-beginners-part-3-on-youtube/ 4. What is the Binary Numbering System https://ladiesandtech.com/2016/04/01/watch-what-is-binary-numbering-system-and-how-to-convert-to-decimal-on-youtube/ 5. Relay Logic Intro https://ladiesandtech.com/2015/12/04/start-stop-motor-circuit/ 6. Relay Logic Intro Start/Stop with a seal  https://ladiesandtech.com/2015/12/04/watch-stop-start-relay-control-circuit-on-youtube/ 7. Relay Logic to Ladder Logic https://ladiesandtech.com/2015/12/04/watch-relaystopstarttoladderlogic-on-youtube/ 8. RSlogix Communication Driver and Configuration Tutorial  https://ladiesandtech.com/2016/01/14/watch-allan-bradley-comms-set-up-on-youtube/ 9. Micrologix500 Communication Set Up Tutorial https://ladiesandtech.com/2016/01/14/watch-allan-bradley-comms-set-up-on-youtube/ 10. Timing Relay Lecture https://ladiesandtech.com/2016/02/11/watch-timing-relay-on-youtube/ 11. RSlogix500 Timer On TON Instruction Tutorial https://ladiesandtech.com/2016/02/14/watch-plc-rslogix500-timer-on-delay-ton-instruction-tutorial-on-youtube/ 12. RSlogix500 Timer  Off TOF Instruction Tutorial https://ladiesandtech.com/2016/02/16/watch-rslogix500-ladder-logic-timer-off-delay-tof-instruction-tutorial-on-youtube/ 13. RSLogix500 Retentive Timer RTO Tutorial https://ladiesandtech.com/2016/02/19/watch-rslogix-ladder-logic-retentive-timer-on-rto-tutorial-on-youtube/ 14. How to do Online Edits in RSlogix500 https://ladiesandtech.com/2016/02/29/watch-how-to-find-and-download-autocad-files-for-allen-bradley-ab-plcs-and-products-on-youtube/ 15. RSlogix500 Counter Tutorial https://ladiesandtech.com/2016/02/25/watch-rslogix500-counters-on-youtube/ 16. RSlogix500 Counter Up CTU Tutorial https://ladiesandtech.com/2016/02/26/watch-rslogix500-count-up-ctu-instruction-tutorial-on-youtube/ 17. RSLogix500 Move MOV instruction Tutorial Part 1 https://ladiesandtech.com/2016/03/14/watch-rslogix-tutorial-on-move-instructions-part-1-on-youtube/ 18. RSLogix500 Move MOV instruction Tutorial Part 2 https://ladiesandtech.com/2016/03/14/watch-rslogix-tutorial-on-move-instructions-part-2-on-youtube/ 19. Rslogix500 Compair Instructions , LES, LIM, EQU etc Tutorial https://ladiesandtech.com/2016/03/17/watch-rslogix-tutorial-on-compair-instructions-grt-lim-equ-les-etc-on-youtube/ 20.How to Create a flashing bit in RSlogix500 using timers https://ladiesandtech.com/2016/03/24/watch-how-to-create-a-flashing-light-program-in-rslogix500-on-youtube/ 21. How to Create a program with a flashing light https://ladiesandtech.com/2016/03/24/watch-how-to-create-a-flashing-light-program-in-rslogix500-on-youtube/  

Greetings, I'm having trouble with a Horner XL4 power cycling itself when 120 V is switched with its relay outputs. I have tried both polarities and slowing down the switching quite a bit. The unit appears to power cycle even when the relay is not switching, and only when 120 V is applied to the relay outputs. I am driving a control 24 - 230 V AC/DC light off an on once a second or so, with the identified/neutral attached to the 120 V AC / 12 V DC PSU. Would anyone be able to guide me into what could be causing this? Thank you.

Several years ago before I arrived at my company, an integrator came in to do the automation on our system. They used a Controllogix 1756-L61S for the safety portion of the project. Apparently, when they completed the job they did not provide the source code with comments, safety password, etc. for anything and it got ugly between our company and theirs. In other words, they would not provide it if we went back to ask them. Allen Bradley has told us that we can not make any alterations now to the safety logic because we do not have the password that was used to create it. And they said there is no longer a master password that you could use like in previous controllers. Does anybody know of any workarounds for this? Or have heard of anything that might possibly work?

I have been using a micrologix 1400 L32bxba. I have had a reoccurring problem of the contacts sticking on the processor. I have added diodes on the coils of the contactors. Using 700CB220EJ relays. I also have the problem of the leakage current being so high it pulls in the relays with the output off. Any help would be appreciated.

I am working on Remote IO panel and plan to use the following components: 1734-AENT 1734-OW4 - qty 2 1734-IE4C I wonder if I need to separate the bus between the relay output module and analog input module? Or anywhere else in this setup? Thanks.

Hello everybody, I'm designing a safety system for a HV power supply. The idea is to use a series of 2 contactors to supply power to the system controlled by a safety PLC. So, it is a typical application. The problem is that the power supply and the contactors are are installed on HV platform, isolated from ground, where the PLC is installed. I think the only possibility is to use an optic fiber link. Does any body know is there is any way to connect a contactor to a PLC output using an optic fiber link, without compromise the cyclical checking performed by the safety module (as I understand, the outputs are continuously check in order to detect wire breaking). The alternative that I have is to use a distributed IO system installed on the platform, connected with a Ethernet Optic Fiber to the PLC: for example using a simens S7-400 PCL with a IM467FO modules (on ground) and a ET200M system with a IM153-2FO module on the platform. But I wonder if there is something more simple and cheaper. Thanks!