Loop reset on DX9100
I need to reset a cooling valve loop on an air handler controlled by a DX-9100.
I see the control percentage change from 0 to 100% constantly after we had a clogged pipe problem cleared. That occurs to me that its a loop trying to adjust to the new conditions and it needs to be reset in order to take correct samples.
There are stil DX9100 out there.
What a tedious controller to work with.
You want to a adjust the reset on a chill water loop?
You'll need the programming software which I think is called gx9100.
Dont quote me on that, its been 9 years since Ive worked with those things. Im glad JC phased them out.
You can adjust the PID parameters in the loop via the inbuilt screen if you have a plug in 'key' - from memory it is button 'z' which scrolls you through the 12 PM Programmable Modules.
You would obviously need some software details to check you have the correct loop, but with alittle investigation and playing you should find the correct one. (The sensor and setpoint are displayed before the PID parameters - check your sensor value, then look for the loop referencing it). The 'e' and 'up' 'down' keys then let you adjust and tune the values.
I believe the controller can still be ordered, but it now comes in a 'black box' and you need the DT screen for interrogation.
I assume you have the original with the built in keypad and screen?
Find the engineering manual on the internet for all of the adjustment details.
I always thought the controller was very clever - one of the PM modules could sequence and rotate eight stages of chilling, all with different duties, and with individual fault removal from the sequence, etc. Never seen any system with one function block come close to that!
Hope this helps.
Hi, if you do not have the DX key for the editing of paramaters in the DX you can use a small jumper or set of needle nose pliers. The "key" essentially jumps the top and bottom pins of the plug located under the flip down panel.
The JCI website is very good and check out the literature to follow the steps. You will find it under digital controllers.
PS. Be very careful if you jump the pins using one of the above methods. You can cause serious damage to the controller if you short any of the others out by mistake.
Originally Posted by Froz'ninWpg
Over the years I have used just about anything to jumper pin 1 and 4....pennies, paperclips, needle noose plier, #12 stranded wire. I was taught to do so by someone who refused to spend $65 for a jumper.
Shorted all pins many of times. Never seen any damage done to the controller and I have never heard of anyone damaging the controller by shorting the pins. I have even seen a DX-9100 where someone shoved a bundle of steel wool in the pin opening. I think that the number 2 and number 3 pins aren't electrically connected to anything.
I have never seen any problem with non-key jumpers on the dx. DX-9100 was designed in the'80s and really had a lot of capability for its time. They have been quite robust for us and could do just about anything you wanted. I found them lacking multistate software points and the not storing user names was unfortunate. Memory was precious when this was designed.
There are some new controllers that maybe "better" today, but I bet a tech who was used to programming a dx could produce a final program, fully test and commission it on a N2 based head end in less time than most of today's more advanced controllers.
Many of the installed DX controllers are getting old though and age does seem to take a toll on electronics no matter how well built. just so much heat and voltage surges electronic devices can take I guess. We are getting some failures especially in hot locations.
That key allows adjustment of the clock and scheduling parameters only.
The changes hes talking about require software.
Setpoints can be edited from the device panel if you have that specific ACO but you would need to find a tech who was very familiar with the devices.
Im sure its part of the building BAS and there is a N30 so why would be accesing the 8454 from the panel
You can edit much more than that including pid parameters from the keypad with a key. As noted above you need to have an understanding of the program. If you have an SX-9100 service tool you can edit almost anything while it is live.
If you think the DX is tedious you should have seen the LCP.
About 8 years ago I took a 2 week course on the DX9100.
Originally Posted by controlgeek
Programming etc. We had to start from scratch and write a program for a 10 story building with boilers, water cooled chillers.
S/S and by pass on every AHU. Reset with return air etc.
I came out of that class thinking that. that controller was way over engineered. Way to "tedious" and dificult and that it would be short lived in our industry.
We had a couple of buildings with it but without using it or doing any new installs I forgot almost everything I learned.
I cant imagine a controller worse than the DX9100.
PM or email me, not too far from you. someone in our office can certainly help you.
My guess is that you need to add a 4seg module to acomplish that reset.
If sense were so common everyone would have it !
Any advice provided is worth exactly what you paid for it, not a penny more not, a penny less !!
I loved them. I could do anything I wanted. I never had a class. I started working on them when they first came to the US from Europe where they were developed.
Originally Posted by Six
You obviously never worked with a DSC-8500.
Originally Posted by Six
UA LU 562
I maintain a lot of DX9100's in this area that were installed by other companies years ago and not maintained. Our biggest problem is it seems like nothing is labeled in them. It makes life a lot easier to maintain the program if you at least name the inputs, outputs, aco's & dco's
They can do quite a bit but remember you can only have 12 blocks due to lack of memory so sometimes a lot of programing tricks to share PID's or other blocks is needed to meet the customers needs which leads to difficult to understand programming.
But as a standalone controller they work good if they do what you want and don't touch them.