Are you sure? you don’t have alarm on PCM?
check with command =>
ZYMO:ET,xx;
local and remote must be 100%
other statistic = 0
NOINSGN incoming signal missing
AIS AIS state has been detected in the incoming line signal (continuous “1-state”)
FALOST frame alignment has been lost
REMOTE alarms from remote end
TOTAL TIME measured total time
AVAIL TIME time of availability
UNVAIL TIME time of unavailability
EFS seconds without errors
ES seconds with errors
SES seconds with a great number of errors
DM deteriorated minutes