PCCC Command Set

I am a 43 year old newbie to the PLC world. I am concurrently doing a course in automation and working on a project at work using a 1336 PLUS 2 drive.

I would like to learn how to decode the DF-1 PCCC Command Set. More specifically I am trying to decode the data part of the message and associate the words in the data message part of the packet with the PCCC command set.


My questions are where can I get information on the PCCC command set?

I do have a captured file clearly showing the messages and responses that I have broken down to the best of my abilities.

Ready to Jump,

BVIGG

DF1 protocol and command set manual:

Here

grs

Hey, that sounds pretty cool. You don't usually think of the Plus 2 drive as a place where DF1 protocol or the PCCC command set get used, but the 1203-GD2/GM2 adapter can translate those into drive commands.

The DF1 protocol manual is the best starting place, but it's not very easy to understand for a first-timer. There are some better sources of information in some of the Drives literature.

Share your data capture and maybe I and others on the Forum can help.

Welcome to the Forum !

I have read this manual and found that though it does well explaining DF1 protocol the PCCC data part of the messages it gives me only part of the answer.

For example, the message 10 02 03 01 4f 00 f3 35 0f 0f e3 73 03 00 00 00 83 08 00 00 00 00 00 00 00 00 00 00 10 03 4f 64 is explained as DF1 protocol for the first 4 bytes (in Black) then the the next 24 bytes (in orange and red) are not explained except for 4f which the command set says is a reply. I don't understand the rest of the data part of the message. Then the last 4 bytes are DF1 protocol.

FYI the above message was a response of the moror controller when a read command was given to read the N41:0 register. I don't know what it tells me about where or what! Ho w can I tell this was the N41:0 register that was read or anything else for that matter?

BVIGG

I have a good Word .doc file that I am unable to post. It has 14 messages captured using Frontline Test Equipments "Netdecoder".

I broke the messages down to the best of my ability but could not post it due to it being in a word document. How else can I post it?

BVIGG

Got it...Here is my capture!

Any Help would be greatly appreciated. I would just hate to give this offer to the "software" guys just yet.

BVIGG

Wow, that's a great analysis. This has only fueled my desire to get my hands on NetDecoder.

The 1203-GK2/GM2 interface to the 1336 PlusII drive acts as an emulator of SLC-500 style integer data tables. It translates those data tables to and from the proprietary "SCANport" protocol that A-B drives use to communicate with their own peripherals.

Your protocol trace shows the controller sending a Word Range Read command to the drive, specifying 10 Words (20 bytes). The drive responds with the values of the emulated integer registers N41:0 through N41:9.

Okay, so what do N41:0 through N41:9 represent in the drive ?

Here's the layout, from the 1203-GK2/GD2 user manual:

N41:0 Logic Command/Status
N41:1 Reference/Feedback
N41:2 Datalink A1
N41:3 Datalink A2
N41:4 Datalink B1
N41:5 Datalink B2
N41:6 Datalink C1
N41:7 Datalink C2
N41:8 Datalink D1
N41:9 Datalink D2

This part of the data table emulation is called the "Producer/Consumer Emulation" because it is data that is usually exchanged with a controller using a Producer/Consumer I/O network like DeviceNet or ControlNet.

This of course begs the question, "what do those things represent in the drive ?".

Get out your trusty 1336 Plus II drive User Manual (mine is the old 1336-PLUS-5.0, August 1997) and turn to page A-13, "Communications Data Information Format".

You will see that the Command Word is a 16-bit array of command bits, and the Status Word is a 16-bit arary of Status bits.

A can recite them from memory; "Stop, Start, Jog, Clear Faults, Forward, Reverse, Local..... " and then I have to get out the manual.

When you Read from the drive, you get the Status. When you Write to the drive, you're sending the Command.

The Reference value is the span of an Integer in a PLC/SLC controller divided by the Min/Max Hz parameters of the drive. This means that a value span of 0 to 32767 represents a frequency span of 0 to 60 Hz (by default).

The DataLinks are just pointers to other parameters in the drive. You will have to go through the HIM module or some other method to read what the definitions are for all of the DataLinks so you can interpret their values.

In the Read message that you captured, the drive is indicating:

Status Word = 3855 decimal = $0F0F hex = 0000 1111 0000 1111 binary.

1 = Enabled
1 = Running
1 = Command Direction Forward
1 = Actual Direction Forward
0 = Not Accelerating
0 = Not Decelerating
0 = No Alarm
0 = No Fault
1 = At Speed
1 1 1 = No Adapter has Local Control
0 0 0 0 = Reference is from Frequency Select 1


The Feedback is the output frequency of the drive scaled from 0-32767.

This value is 29667, so if the drive is set to the default Min = 0 Hz and Max = 60 Hz, the drive is indicating that it is running at

29667 / 32767 * 60 = 54.3 Hertz.


The definition of the other Data Link values depends on what parameters those DataLinks have been defined to represent. Because you are reading from the drive, these are the parameters numbers defined in the "Data Out A1-D2" parameters.

Ken is on track, I seem to remember, as he stated, there is some conversion involved, does the drive report units in drive measure?
I seem to think that hex response is according to the drive E units, ie. if drive max f out = 400 Hz so 400 Hz represents, 32767 input reference.
Just a thought...

Bitmore

Aahh to be the master and not the student to me is divine.

I think I am going to change my avitar to a grasshopper!

You have brought the key and now I shall study and learn.
"Understanding is the beginning of Wisdom"

I will knock off these messages first by studying the manual and also checking my parametersand then check on that conversion to see what thats all about.

Ken, If you were here I would have brought you a donut or something.

I'll keep you both informed after the holiday.

Much Gratitude.

BVIGG