Anyone have any idea what this means in the syslog and messages

May 20 10.31:27 sco9 SX: command stack - completing 22 requested 24
device 1

might have something to do with the specialix serial SX cards
installed , but I can detect no problems all serial comms ar e working
and all ttys , similar message on July 1st

system is SCO 5.0.7

many thanks