Interfacing Honeywell UDC 3300 Temperature controller

[Shanky]

hi J.A.C,

Instead of working with RS485, I decided to buy the black box converter. Now everything is connected and I am trying to interface with the Honeywell. I have done other interfaces with many equipments, I dont know why I find Honeywells manual to be totally complicated (Might be just me who says this).

I guess I have the right jumper connections. I am able to read the Process Variables and setpoints from the UDC 3300. In the response message from UDC for setpoints and process variables, it gives the values correctly. The message format is something like this:

_ _ _ _ _ _, Identifying code, Value, CR LF.

the first 6 characters are 0080C0 or something like that. I do not get a 0000_ _. I guess the second two numbers 80 represent some error too. I am not able to find the cause, but I am getting the values of PV, SP though. Also, i am unable to change anything in the controller ie, write anything to the controller. Does the controller need to be explicitly put in remote mode from local mode.

Could anyone explain me how to proceed? I finally want to run individual SP Ramps from the computer and turn system on hold accordingly. I downloaded some UDC 3300 sample programs from NI website but were using modbus as communication. I want to communicate using RS232 from honeywell but the sample programs do not have that option. I wrote own VISA read and write for 232 communication but as is the case am not able to write anything to the controller. I am just able to read from the controller.

Any help in this regard is highly appreciated,

Thanks

Shankar

[J.A.C]

Hi Shankar,

For me, the black box was very quick to connect and it works for me. I am wondering why you should be facing problems.

well, initially i too found Honeywell manuals complicated, but that could be because there are many different manuals for this controller. 

OK, The first thing to check for is the jumper connections. For reading and Writting to UDC3300, you need to have the connections as :

JUMPER  SETTING
XW1A  DCE
W8  B-C (2-wire)
W15  B-C (Data Enabled)
W5  A-B (RTS/CTS delay - normal)
W9  C (0 msec)
W17  C (2 msec)
W16  B (0.1 msec)
S1  OUT (Normal)
S2  ON (RS485 Receiver Terminated)
S3  ON (Line Bias On)

Also note the settings in your controller. The Baud rate, should match the one set in the controller. Also i used the modbus protocol, though the Black box converted is connected through the RS232 to PC. Once the jumper settings and the settings in the controller are fixed, i think you should be able to read and write to controller.

[Shanky]

Hi J.A.C,

Thank you for your help. I found that my mistake was in making the data frames for ModBus. One quick question: Once I start the SP Ramp in UDC 3300, I am not able to read the setpoint value. it always gives me 36C and never increases with the local setpoint increase in the panel. Once I disable the ramping, the program reads the setpoint correctly. Cant we read setpoint values in realtime when the SP is ramping at the same time? PLease do let me know.

thanks for all your help,

Shanky

[J.A.C]

Hi Shanky,

Here is what i understand:

Suppose you want to go from SP1 to SP2 and you start the ramping process you are not able to read the intermediate SP. I guess it is possible that during the transition you may not be able to read the SP value. This could be because the controller may just be displaying the intermediate values and not storing it to the SP register (from where we read it in LabVIEW, this is my wild guess and have no proof to support it, neither i am a embedded programmer !. You could also talk to Honeywell for this). Hence in that case you may not be able to read the intermediate SP value. But once SP2 comes in an acceptable range (stabilizes), you should be able to read the SP (SP2 rather). Though, I am not sure about this. (Again wild guess)

My application requirements were simple and i had to just read PV and write SP to the controller. The ramping values i guess were the default ones ??. Right now i do not have the setup ready with me or i could have tested it.  Though you could experiment with it and let us know your results if you come across something interesting.

Hope this helps and All the Best !.

J.A.C

[jknight_ve]

hi there , im trying to communicate with a UDC 3000 but a get no response from the controller , and i test mi program and it sends and receives data , i have the next configuration in the controller

half duplex , 9600 Baud, comstate = Rs 422/485 , Shed = 30, tx delay = 2
 and i send the next message: 03,0204,E4,18,120,HH\13
Im not using a balck box converter im using a normal conventer Rs 422/485 to Rs 232, i don't know why isn't sending the data do i need to make some delay with software to see the data?,so i need help please


Tomás Estrada

[O_Proulx]

Hello,

Did you look at the LabVIEW driver on idnet.  You can also look at this document for more on finding and installing instruments drivers. 

Have a great weekend.

[jknight_ve]

hi yes in that appears the udc3300 drivers but im trying to communicate with a UDC 3000 , and the problem is that it doesn't suport modbus protocol is a kind of old controller so i need to know if someone has made the communicaton with the UDC 3000 so they can give some advices, im doing my program and i tested, it sends and receives data but when i sent data to the controller i get no response ...

Tomás Estrada





Message Edited by jknight_ve on 04-12-2008 05:30 PM