英文原文是这样子的：
c/m: 0 =Timer is an inter-character timer.
1 =Timer is a message timer.
tmr: 0 =Ignore SMW92 or SMW192.
1 =Terminate receive if the time period in SMW92 or SMW192 is exceeded.

SMW92 SMW192 Inter-character/message timer time-out value given in milliseconds. If the time period is exceeded, the receive message function is terminated.

意思就很清楚了。