The preferred solution here is to use Motor Starter Protectors instead of plain old overload relays. They give the best of three worlds (or 4).
First, an aux contact from the MSP can go to the PLC to indicate an overload trip for one, but the MSP itself trips and disconnects the motor.
Second, the MSP's we use have nice switches on them and even little lockout tabs, so a motor can be manually shut down and locked out.
Third, related to second, we use an aux contact off the MSP (not the overload trip contact) to indicate back to the control system that the starter is manually commanded off. That's useful to bypass alarms, or do some interlocking based on a hardware off command.
Fourth, the MSP's are rated as full circuit protection devices, eliminating the need for external breakers or fusing, and they bolt directly to magnetic starters to save wiring.
Fifth, I guess, is that where we don't need magnetic (controlled) starters, the MSP's are just fine by themselves as manual starters.
Oh, the original topic? I generally don't like using a PLC to interlock a motor-starter overload, but rather just to indicate that one has occurred. It's too easy for someone in a hurry (and anonymously) to force the input on, or hard-wire it on to prevent 'nuisance trips', which can lead to fire or other severe damage.