So I assume you have setup a Custom function so that when the PV hit 360 the CF will set PV to 0? Does it do something else?
You may want to try this: use a non-differentiated custom function to monitor the PV value continuously, if it goes negative, then execute a HSCDEF again to change the target PV to -360 and turn on a lock out relay so that it will not execute this custom function again (to prevent continuous execution of the HSCDEF statement). Once the interrupt service routine works, set PV to zero clear the lockout relay so that it will again monitor the PV for a possible negative value.
I haven't really tried it, but I think it should work. Call me at 1-877-689-3245 if you need more assistance.