Check the transceiver and make sure it is jumpered for SQE.

Also do a LINKCONTROL @;STATUS=ALL

Look at the statistics for the DTS LINK.  If the HEARTBEAT LOSS is not
zero, then  SQE may be disabled on one or more than one device (I.E.
HPe3000 also).   On the smaller boxes, that can sometimes cause problems.


Have you done a power on reset of the DTC?