Does the drive have a HIM (keypad/display)?
If so, you can probably figure it out by trial and error, and can certainly use a PlusII manual or virtually any other 1336 manual and get in the ballpark.
From memory, on the HIM, use the keypad (ESC key 1st I think) to find the "PROGRAM" function (not "DISPLAY" as it is read only), then navigate to "SETUP", then I think you will find accel and decel times in that short list of parameters.
When you find the one you want to change, press the enter symbol key EDIT: Or maybe the SELect key...I forget, and you should see the cursor move to the parameter value. Use the arrow keys to change it, and press enter to accept the new value.
Hope this helps...
If you are using some sort of communication interface to MSG parameters to the drive, give us more information about the devices connected to the drive scanport or comm interface...
Paul
EDIT: I, too, have had some trouble finding specific 1336 books at ab.com. I think that I had better luck going into the literature library from a different angle (like product selection first, then backing into it.) I remember searching for "1336" from the lit. library didn't find everything I have needed in the past.