SLC to Micrologix 1400 messaging

[Ferroresonance 0]

Greetings all I have a messaging project i need to setup. The decision has been made to retire one of our SLC 5/05s and replace it with a micrologix 1400. The old SLC was only used for messaging and has no I/O. I understand that if i want to read/write from the micrologix to the SLC then i need to set up the target device as 500CPU, but what about read/write from the SLC to a micrologix what do i set up the target device as? SLCCPU,PLC5, or a CIF,? Also does anyone have any tips on a sucessful migration from a SLC to a micrologix in the MSG instruction?