A.3 I/O Configuration
101
A.2.6
Acquisition
•
less than 5 minutes with current almanac
•
less than 20 minutes without current almanac
•
greater than 20 minutes in areas where antenna has limited or obstructed view of sky
A.3
I/O Configuration
A.3.1
Timed Outputs
Outputs: Four, each with BNC and 5-mm pluggable terminal strip in parallel. Output Select is
jumper selectable between unmodulated IRIG-B, 1 Pulse Per Second (PPS), and Programmable
Pulse. Output Mode is jumper selectable between 300 volt FET, modulated IRIG-B, and 5 Vdc
(250 mA at
>
4 V). Note that Programmable pulse is divided between Programmable Pulse A on
outputs 1 and 2 and Programmable Pulse B on outputs 3 and 4. The MOSFET output is not
electrically isolated from instrument common.
A.3.2
I/O Connectors
Each timing output has one BNC and 5-mm pluggable terminal strip in parallel. Event Input is
BNC and DB-9M.
A.3.3
Standard Output Signals
•
IRIG-B 003 and 000 (now 004), unmodulated
•
IRIG-B 123 and 120 (now 124), modulated
•
1 PPS; Programmable Pulse
•
300 V FET switching
A.3.4
Input Functions
Input functions included one Event Input. Input connector is dedicated BNC or either of RS-232
connectors (COM1 and COM2).
A.3.5
Event Input Timing
For a received data message, the leading edge of the start bit may be selected to trigger the event
input, providing synchronization with 0.1
µ
s resolution.
