Film-Tech Forum ARCHIVE: A better explaination of the CP750 ACSII Command Set

This is topic A better explaination of the CP750 ACSII Command Set in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Owen Morgan (Member # 7854) on 10-02-2013, 08:20 PM:

Hello Everyone,

As always, this is THE place for help!! [Smile]

I was just wondering, at the back of the CP750 manual is the full ASCII command instruction set. I am however struggling to decipher what some of them actually do..... for Instance Fader_delta can have a lot of different interpretations as to is usage (I believed it to mean change the fader level by a defined delta value.... implying delta to mean 'change in'....)..

A lot of the functions are not, if at all described very well.... Is there anywhere where the meanings of the ASCII commands is defined (like some form of syntax guide, like for coding languages)?

You may say, if I don't already know, then I shouldn't be meddling etc... but my response would be, how am to learn in the first place?

So is there a full ACSII command set definition guide?

Thank you in advanced!

Owen.

Posted by Brad Miller (Member # 2) on 10-02-2013, 09:50 PM:

Owen, do not start your posts with "RE:" like a response to an email.

If you are responding to an existing thread, then reply to it. Don't start a new one.

Likewise don't start new threads giving the impression they are a response.

Posted by Dave Macaulay (Member # 813) on 10-03-2013, 07:37 AM:

The command set as listed is pretty much completely. There are a few commands not in the list I have, for features added after the manual was published: the 7.1 commands for example.
Nobody I know of ever uses 99% of the commands. The CP750 control program probably uses most of them, but when would you want to control the EQ or any number of other commands otherwise?
The only commands I've automated are input mode and fader level, plus the 5.1/7.1 switching. I have tried sending decode method commands as well for the 2 channel digital and non-sync inputs but no cinema has used these as far as I know.
I don't know what problem you're having. You just send the command and termination string, and the processor does what you asked.
If you want to know the effect of some obscure command that has no use in normal automation, I'm no help.

Posted by Steve Moore (Member # 4753) on 10-03-2013, 11:31 AM:

Dave, does this mean you have worked out a string to switch the digi 1 (AES) input to a "sort of" pro logic mode? My day titles are stereo only from my server, and i tried to work out a method of switching that to give a form of decoded surround from the left and right and then switch back to discreet. I have worked out the 5.1/7.1 switching and thats fine. If you have mastered this one, a string would be much appreciated.

Posted by Marco Giustini (Member # 4544) on 10-03-2013, 02:28 PM:

On the CP750 setup sofrware, go on Avanced/Expert view (if memory serves).

ALL the commands are listed there and those are actual commands.

Posted by Owen Morgan (Member # 7854) on 10-03-2013, 07:28 PM:

Hi everyone,

Thank you for your responses,

What I'm really asking is the commands are listed, both in the manuals and the expert view, but the 'Definitions' of the commands is vague....

My example for delta_fader was that its not explained what delta_fader actually does..... other than this is the delta_fader command and its values range from -100 to 100.....

does that make sense?

Cheers,

Owen.

PS. the only real reason for asking is just to make sure that I'm not underutilising the macro potentials if you know what I mean. I wanted to create a slow fade out (the mute_fade_out_time limit of 5 seconds is in my eyes not long enough.....), however, I can't insert a shed load of fader commands, if I don't know what the original fader level is set to (otherwise, I could end up making it louder before fading out which kinda defeats the point!!)....

Posted by Carsten Kurz (Member # 5396) on 10-14-2013, 08:18 AM:

I'm currently trying to 'emulate' a CP750 on our AP20 in order to control the AP20 through serial from a Sony. I have hooked a Hypterterminal PC to the Sony to find out what is going own. The Sony sends an initial CP750.sys.mute ? request to the processor to find out wether it is actually connected. So far I wasn't able to answer it correctly it seems. I guess there is no more documentation on the serial protocol, you simply have to find about about the commands yourself. The docs say there is a 'simple' and expert mode (the latter one giving you control about configs, etc. as well, not just format and volume).

I'm currently reading the CP750 manual ver5, but I find no mentioning of a termination character. As I do not have a CP750 for testing, I'm stuck. Another cinema nearby has CP750, I might go there for some testing. I'm only after volume cues.

- Carsten

Posted by Steve Guttag (Member # 268) on 10-15-2013, 11:34 AM:

I don't believe there is a termination character.

Posted by Carsten Kurz (Member # 5396) on 10-16-2013, 09:00 AM:

But it does expect something like CR/LF after a command?

- Carsten

Posted by Steve Guttag (Member # 268) on 10-16-2013, 09:26 AM:

I don't believe so. I think when it receives the right sequence of characters...it acts upon them.

Posted by Carsten Kurz (Member # 5396) on 10-16-2013, 06:09 PM:

Okay, I guess it's best to do some testing on a physical CP750 then.

- Carsten

Posted by Owen Morgan (Member # 7854) on 10-16-2013, 08:23 PM:

I suppose then, from my original question at least.... Dolby provide the command list, but then somehow expect you to magically know what everything does and how it works?

Ahh well.....

Thanks all the same!

Owen.

Posted by Pete Naples (Member # 761) on 10-17-2013, 12:45 AM:

quote: Owen Morgan
Dolby provide the command list, but then somehow expect you to magically know what everything does and how it works?

That's where 20+ years of industry experience comes into play [Wink]

Posted by Owen Morgan (Member # 7854) on 10-17-2013, 09:28 AM:

Hahaha!

Just a shame if your trying to start your 20+ years experience!! I can't learn as much as I want to!!

Wow that sounds very nerdy!

Thanks,

Owen.

Posted by Steve Guttag (Member # 268) on 10-17-2013, 10:24 AM:

I dunno...I often have to "play" with a particular box to see just what it wants from its command set. Rarely do things just work since the engineer that came up with the system may not think the same way I do.

I have not had any issues with the CP750 commands with 3rd party stuff either. It just seems to work. Heck, there is a guy with a CP750 App for your smartphone that uses those commands just fine too.

I guess what I'm saying is...the CP750 isn't that hard if you know what you are doing with serial/TCP commands, in general.

Posted by Owen Morgan (Member # 7854) on 10-17-2013, 01:16 PM:

I agree that if you know what commands you want to use its not too hard, heck with our doremi its a sitch to send text serial commands to the 750, its just that the manual doesn't do a good enough job in instructing you what the commands do..... ? I think it an under sight by them, as it means the devices might not be being used to their full capability......

Ahh well, we live and learn!

Thanks

Owen

Posted by Marco Giustini (Member # 4544) on 10-17-2013, 01:30 PM:

Owen,

most of the commands are self-explanatory if you know the 750 and how to EQ a room. Most of the time you won't need to use the ones you don't understand, the 750 is a simple device and 99 out of 100 you need to change the format, set the volume, fade the sound. I can sort out what cp750.sys.eq_l_6_3k means, but I doubt I'll ever need it!

Posted by Owen Morgan (Member # 7854) on 10-17-2013, 01:41 PM:

True, I can see most of them are Eq settings,

but the ones in question really are:

ctrl.fader_delta
state.dialnorm
sys.cinema_system_text
sys.comment_text
sys.cp_text
sys.dolby_digital_dialnorm_1 (through 4)
sys.mic_text

Although I'm sure some of them are useless, the manual offers no explanation as to what they do.....

Sounds stupid, but really all I'm trying to do by looking at the manual is know that there is nothing else I can do! ie. vindicate myself in knowing that any and every possible feature that could be useful is available!

Cheers,

Owen.

Posted by Marco Giustini (Member # 4544) on 10-17-2013, 03:36 PM:

Dialnorm

Posted by Owen Morgan (Member # 7854) on 10-17-2013, 03:44 PM:

Thank you,

I have learnt something new, that is at least good!!

I also have a feeling that the 'text' ones are to do with the description text used on the CP750 software home, and not anything interesting like a serial text response! So the list is finally narrowed!

Thank you very much,

Owen.

Posted by Carsten Kurz (Member # 5396) on 10-17-2013, 03:45 PM:

Delta Fader should just be a relative offset from the current absolute Dolby Level.

Set absolute Level to 6, adjust by +/-100 could mean from 5 to 7 - just try it.

Most parameter changes should be reflected in the Display at some time.

Some manufacturers have full documentation on these things, others not. In the case of the CP750, it's just that the use of remote commands is not strictly meant to be performed by end users, but by integrators - and they usually know how to find out or who to ask.

- Carsten

Posted by Owen Morgan (Member # 7854) on 10-17-2013, 03:57 PM:

Hi Thanks for your responses,

I can kind of understand the thing about the commands being used by integrators and not end users, I suppose its just a shame when the end user would dearly love to work as an integrator (and maybe beyond with an electronic engineering degree)when I do finally graduate!

Thanks for everyone's help in understanding things!

Thank you,

Owen.

Posted by Carsten Kurz (Member # 5396) on 10-17-2013, 04:12 PM:

I know what you mean. As I said, some systems are well documented, some need a certain level of re-engineering. Which can be fun.

- Carsten

Posted by Marco Giustini (Member # 4544) on 10-17-2013, 04:26 PM:

These days 99.999% of end users barely know what the CP750 is unfortunately.