External Gate; Application Sequences; In T Er Val Time R - IBM Series 1 User Manual

The timer I external gate is the input for the user-supplied
gate signal. It is
only
effectiYe when the external gate
control is enabled. This input uses the down level as
active, not the down transition.
Timer X run is an output signal that indicates the timer is
in the run state. Its primary purpose is for state
synchronization of the timer X external gate cycle. The run
signal becomes active with a start Timer command and remains
active until (1) a Stop Timer command is accepted or, (2)
the timer X external gate signal becomes inactive, or (3) a
halt/reset occurs.
Timer
!
External Qate Enable
Timer X external gate enable is an output signal that
indicates the external gate has been enabled through bit 15
of the Set Timer "ode command.
The timer attachment digital outputs are a solid state
switch that can be used with or without a customer source
voltage. See "Drivers" in the "Electrical Characteristics"
section of this chapter.
The timer attachment digital inputs are TTL co~patible.
A jumper-wire option is available on the card to provide a
filter for these inputs if required in a noisy environment.
A loss of frequency response is the result of using the
optional filter. Without filtering the input rate can go to
1 MHz. With filtering the input rate drops to 50 kHz worst
case. For additional information, see "Jumper Selections
1l
in the "Physical Characteristics" section of this chapter.
APPLICATION SEQUENCES
Interval
Ti~!:
The following steps apply when the timer application is an
interval timer using an external time base (customer clock
input) •
3-6 GA34-0033