In order to recall the presets on all the C2 units where availiable (except the 5000 and 4000 - see here C2-5000 Preset RS-232 control compared to C2-7000) two serial commands are required. For the preset recalls you will need to send two commands the first being the Preset to work with and the second command is the action, in this case Load Preset.
Don't forget all the commands below are in ASCII and must be terminated with a Carridge return.
Set Preset 1
F04104102250000017D
Set Preset 2
F04104102250000027E
Set Preset 3
F04104102250000037F
Set Preset 4
F041041022500000480
Set Preset 5
F041041022500000581
Set Preset 6
F041041022500000682
Set Preset 7
F041041022500000783
Set Preset 8
F041041022500000884
Set Preset 9
F041041022500000985
Set Preset 10
F04104102250000108C
Load Preset
F04104102260000017E
Further information on the serial protocol can be found here :RS232
Control over CORIO2 units