ABB DSAX 110 3BYN266801009脉冲编码器
读取计时器有两种方法：计时器锁存命令和读回命令。计时器锁存命令计时器锁存指令允许读取“动态”计时器，而不影响过程中的计时。与控制字一样，定时器锁存命令被写入控制字寄存器（I/O地址$503，见表4-1）。选择定时器位（ST1，ST0，见表4-3）选择三个定时器中的一个，而读/写位（RW1，RW0，见图4-4）选择定时器锁存命令，RW1=0和RW0=0。在发出定时器锁存命令时，所选定时器的计数被锁存到0L寄存器中。计数保存在0L锁存器中，直到读取。多个定时器锁存命令可用于锁存多个定时器。同样，每个计时器的计数被锁存，直到被读取。
Reading There are two methods for reading the timers: the Timer Latch Command and the Read-Back Command. Timer Latch Command The Timer Latch Command allows the reading of a Timer ‘on the fly’ without affecting the timing in process. Like a Control Word, the Timer Latch Command is written to the Control Word Register (I/O Address $503, see Table 4-1). The Select Timer bits (ST1, ST0, see Table 4-3) select one of the three timers while the Read/Write bits (RW1,RW0, see Table 4-4) select the Timer Latch Command, RW1 = 0 and RW0 = 0. The selected Timer’s count is latched into the 0L registers at the time of the Timer Latch Command. The count is held in the 0L latches until it is read. Multiple Timer Latch Commands can be used to latch more than one Timer. Again, each Timer’s count is held latched until it is read.
