2707-M232P Dtam Communication Problem

We are trying to download a file from our PC to a 2707-M232P (Spectrum / AB) DTAM. We have checked the following conditions:

Dip Switches-OK

2707-NC2 Cable - Correct Version DPS Software - Correct Version DTAM is at the correct screen waiting for download.

We run into the following problems:

When we attempt to transmit on Com1 we get: "Receive Error Found Type

79"

When we attempt to transmit on Com2 we get: "Operator Quit Acknowledged"

Any ideas/help appreciated.

Thanks