I think the only way oyu could accomplish that is to use PCCharge as a
standalone app rather than having it integrate with RMS. RMS is only
going to ba aware one Merchant Account per register, so I don't think
there's going to be a way to assign the account based on tender type when
it makes it's call to PC Charge.
Also, you would need additional licenses to add merchant accounts in PC
You will need 1 Merchant ID for Visa/MC, 1 Merchant ID for Amex/Diners and 1
Merchant ID for Discover (standard practice).
In RMS if you use the Citibank option it is actually going through VITAL and
you only need to enter the Merchant ID for Visa/MC in the RMS software.
VITAL actually uses the Visa/MC Merchant ID as the master number and does
the other processing using the other Merchant ID's for you.
Actually, you only need 1 merchant account to process Visa/MC. Yes,
you do have an additional account for Amex/Disc/Diner Club but Nova
would actually handle that and in your merchant profile at Nova, it
would be noted that you take those cards. So, you only need one
merchant account in PCCharge.
Now, PCCharge allows multiple merchant accounts but RMS does not so
you can only use one merchant account when using RMS unless you have
multiple copies of RMS running to 1 PCCharge server.