Mitel SX-200 EL Technician's Handbook page 144

Technician's Handbook
9. Connect the customer's PMS computer to the Dataset's RS-232
connector.
10. Verify that the customer's PMS computer communicates
with the PBX.
If the PBX's PMS interface and the customer's PMS computer
n
communicate properly, you will see an exchange of ENQ
(Enquire) and ACK (Acknowledge) commands at the customer's
PMS computer.
If the PBX's PMS interface and the customer's PMS computer
n
do not communicate properly, test the PBX's PMS interface.
Refer to PBX and PMS Cannot Communicate (page 89).
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