mjrx

Hello all, I have an Micrologix 1200 with 3 1762-IF 4 modules. The 1200 PLC recently failed and I put a new one in and loaded the same running program. When going to run, it faulted saying the program was set for modules not found in the PLC or modules were found that were not configured in the program. When I go to IO configuration in RS500, there all in there, but when I do the "Read IO Configuration" button, it comes up empty, it doesn't find the connected IF-4's. I am suspecting maybe the cards got damaged too? Or am I missing something?

Does anyone know, when you plug a new 1762-if4 analog card into an ML 1200 PLC, will the LED on the if4 card go on right away, or does the card have to be fully configured first before the cards LED will turn on? Of course I would think that it should powerup straight away, or how could it be configured without power.

I am trying to connect an HMI direct to a Mits F700 inverter and talk via Modbus. I can connect, and read/write to any of the parameters (41000 - 41900) with no problem. The problem starts when I try to write to any of the modbus regs that control it, namely speed/hertz value register 40014. I can read it fine, but when I try to write to it it returns an exception error. I have put aside the HMI and am using Modscan right now and I get the same thing - read OK, write doesn't go. I am tapping the data, the request goes out with function 06 (it looks just like the parameter writes) but returns 86 with a code of 03, which I think means bad data but I dont think so as I am reading a value like 4555 (which is 45.55 hz) and I try to write the same value, or even a value like 3535 it throws an exception. Anyone come accross this? I have successfully used a QJ71MB91 to write to these drives and never had any problem, and I know the 'MB91 card also uses function 06.

I have a motor feedback encoder going to back a servo drive. I need to also wire that same encoder to a PLC counter card to monitor position. There is not an encoder out on the servo to use for this, as some servos have. To complicate matters, I need this encoder to also go to a second redundant PLC. It cannot be switched between the PLC's as it needs to be live to both PLC's so the redundant PLC can keep track of position - in the case the redundant PLC gets called to action, it needs to know where (position) the other PLC left the machine. So in a nutshell I need one encoder to be paralleled across three devices. I know I just can't parallel them because of possible voltage level differences, loading issues, feedback problems, etc. Is there some COTS isolation device I can use for this, do I have to get creative with diodes, or other iso method I could try? Thanks in advance.

I have been tasked with cooling a large motor. It has a VFD controlled cooling fan. There is an RTD at the intake area and another RTD after the airstream passes the motor. There is also a heat exchanger in the airstream that has chilled water passing through it. It also has an RTD at the water inlet and another RTD at the water outlet. The water flow through the exchanger is controlled by a modulating valve. My question is what type of control algorithm might be best for this arrangement? Should it be some type of cascade control, a single PID, differential, ??. It seems seperate PID loops may interact with each other and be hard to control. All 4 RTD's and analog to the VFD and valve are in place in my PLC and ready to go, I'm just not sure which way to go. Thanks in advance.

Yes, thanks for the reply. I got it sorted out, in the drive I needed to set the number of bytes I wanted to send to the devicenet card.  I was trying to read 8 points, but the drives default was 4 with instance 71/21.

Trying to setup devicenet 1756-DNB to F800 mits drive. Have the eds file, everything seems to go ok but the module comes up in error 77 for that node. Is changing an eds file something that is normally done when setting these up? 

Thanks. I didn't need to run loads, just needed to make sure the drives came to life. Just a temporary test on a panel that hasn't been used in some time, and it's offline in storage with only 240 single phase in house (I had a 480/240 transformer to convert to 480). Yes, I found they power up on single phase across L1 & L2. I have used Mits a lot and they work like this too. 

Can anyone tell me if a 480V PowerFlex VFD will at least powerup on single phase 480V? I need to make sure the VFD's at least light up in a panel full of drives, there is no 3 phase available but I can feed them with a 120 - 480 single phase xformer, so L1 & L2 will have 480 to them. No loads are hooked up, so theres no danger of that. Just trying to see if the drives power up right now.

Ok, thanks very much. I should have considered that.

Anyone on where I can locate a driver for a 1784-PCMK series A card? Thanks.

Very nice cbvance, thank you. That was the general direction I was heading, after some simulations I have run I have ruled out cascade control. I also was thinking about a single loop to control both with a seperate gain value to give more "weight" to the water over the air temp, kind of like making the vfd a slave follower to the water temp PID loop.

Thanks for the help.

Now that the price of SSD's have come down so much, I have ordered a few to update some workhorse laptops that we use in the field. I then wondered if, when cloning the existing drive, would all of the licensing transfer over as well, specifically RS Logix. If the license is somehow linked to the drive's MAC ID, then I would think there may be an issue. Anybody run into any issues or have any tips on cloning a complete hard drive?

I have RSLogix 500, FactoryTalk, and GX works 2

Please don't read into my original post as a way to get around any licensing. I have paid hard earned $ for my licenses, and kept them up to date. So if I need to de-activate the license and then re-activate it on the new drive, so be it. I just wondered what, if anything, I will run into. Thanks very much.

I have several 3 wire rtd's about 50 feet or so from my Plc input module. I was planning on using a high quality 3/c shielded cable for them. Is this acceptable wire, or is RTD wire necasary for this? Thanks.

Its just an incremental quadrature 1024 ppr encoder, used for feedback between motor and drive. I found an encoder signal broadcaster that takes one encoder input and rebroadcasts it, optically isolated to up to four different devices. It is made by BEI. Thanks for the answers, I am now leaning more to a seperate encoder, and it will probably be a 16 bit absolute type.

I occasionally get major fault 0008 on a ML1200. It just says its a a non-user error a "fatal internal software error". Can anyone shed any light on what this error means, and how to remedy it?

I have 4 ML 1200's on a radio network. I am using Ch 0 serial, running half dupex slave 9600 N81. I have tried No Handshaking and half duplex modem, and about every timer setting in there. What happens is all is well for quite some time and then the serial port locks up with no errors, and the PLC continues to do its thing running the local process. Sometimes it will restart and start running again on its own, but cycling the power to the PLC will always get it going again. Its like a buffer is getting full in the ML1200 or something. At first we thought it was the radios, but have definitely found it is the PLC. We are not transmitting much data, about 24 bits and a dozen or so words, and each radio gets polled every 15 seconds. This one is kickin' my butt. Anyone have an idea?

I was going to start playing around with this code, I'm interested in turning raw vibration accelaration data into freq spectrum for analysis. Just glancing at the code, there appears to be variables in the code that are not defined in the Symbols .pdf. In code, w_complex, I assume this is w_imaginary, same for code has x_complex and tmp_complex, .pdf has x_imaginary and tmp_imaginary. Since I need to update this spectra trend alot, and it seems very CPU intensive, what would the effect be if I modified the code to eliminate the for and while loop, simulating the for/whiles but doing it during the PLC scan (like just decrementing or incrementing the variable and exiting the FB, so I don't get hung up in the FB)?

Have used the qterm a7 in a class 1 div 2 app. I like the HMI, but the Dev. Environment for it I absolutely hate (iX Dev), it's the worst, slowest, painful, buggy HMI software I've ever used. Back up often during development.

I need to change the IP addresses on a CompactLogic L32E and PV+ 1000 from a 10.10.1.x subnet to a 192.168.1.x subnet to match an office LAN. What are the basic steps to this, I know I can change the HMI's IP from the PV's setup menus, but what about the PLC and driver? As painless as possible? Thanks.

Thanks for the info. I don't yet have the program, but I believe it is just the -L32E and PV+ 1000. I struggled trying to setup a router to access different subnets (the office is 192.168.0.x and the PLC/HMI subnet is 10.10.1.x) in order to VNC into the PV+ and remote into the PLC with their SCADA but it quickly became a nightmare. People have told me this is possible, but I am convinced now it will be a maintainence headache for anyone in the future. Changing the PLC & HMI IP's is the way I have to go.

I need to put a SLC 5/04 on an existing SCADA network. The DF1 port is presently occupied with an HMI. I have to interface to the DH+ port. Problem is my existing network is configured for 19200 N81 serial (DF1). What are my options for this interface? I would imagine some type of protocol converter ???? Thanks in advance.