Simon,
The AT commands for the NM-AM-V2 modems are documented here:
http://www.cisco.com/application/pdf/en/us/guest/products/ps275/c1049/ccmigration_09186a00801e6fc4.pdf
The specific command to configure them for V.22 is
"AT+MS=V22". You may also want to mix in commands to
disable error control (+ES=1,1,1), reset to factory
defaults (&F) and autoanswer (S0=1).
The recommended method for configuring a modem is to
use autoconfigure. http://www.cisco.com/en/US/tech/tk801/tk36/technologies_tech_note09186a008009491b.shtml#configmodems
Putting it all together, you might use something
like this:
term monitor
debug confmodem
config t
modemcap edit V22 misc &FS0=1+MS=V22;+ES=1,1,1
line 33
modem autoconfigure type V22
Cheers,
Aaron