Arbiter Systems 1088A, Operation Manual

Page: 85 / 279

Chapter 8
Relay Contacts and Event Inputs
8.1 Relay Contacts, by Option
Model 1088B can supply relay contacts through installation of an optional accessory. Option 19
provides one Form C (SPDT) set of contacts that can be used for the Out-of-Lock function. Option
29 provides four additional timing outputs and has two solid-state relays available with output
multiple functions and +25/50 Vdc supplies. For additional information on relay specifications and
operation, please see Option 19 in Section C.15, and Option 29 in Section C.20.
8.2 Event Inputs
8.2.1 Event Timing Input
When configured for event timing, the 1088B can provide two input channels with 0.1 microsecond
resolution. These two channels are called Event A and Event B. Event A is primarily used for
synchronization via the RS-232 port with an external computer or other type of device. It may
also be used to time an external 5 V CMOS signal applied to J4; see Figure 5.1 and Section 5.2.2.
Event B may only be applied to J3 and must be a 5 V CMOS signal.
Data for individual recorded events can be recalled using either the Event/Deviation key or via the
RS-232C interface (see Section 9.2.2). Data for each event will be retained until it is retrieved using
one of these two methods. Thus, if no event data points are retrieved, recording will be suspended
when the total number of events per channel reaches 200. As soon as data is retrieved for a recorded
event, its address (001 - 200) is made available for data corresponding to a new incoming event.
8.2.2 Event Timing Latency
Event data are recorded using a high-speed capture circuit operating with a 4 MHz time-base.
Latency is limited by the interrupt processing speed of the clock’s microcontroller, which in turn
depends on its workload at the time the event is received. Since the workload varies from time
to time, latency likewise varies. However, response time will, in general, never be less than a few
hundred microseconds nor greater than 10 milliseconds.