EndRun Meridian II, User Manual

Page: 123 / 240

M e r i d i a n I I U s e r M a n u a l 102
C H A P T E R T E N
103 M e r i d i a n I I U s e r M a n u a l
R E A R - P A N E L I / O
Or, you can use these console port commands:
Command:
cpuio
MeridianII reply:
PROGRAMMABLE PULSE OUTPUT is Installed
Current Setting = OFF
Command:
cpuioconfig
MeridianII reply: Interactive script is started so you can change the pulse rate.
Trigger PPO Function
When the PPO option is installed on the CPU Module, then the
triggerppo
command is available
via the console port. (The trigger PPO function is not available on option modules.) The
triggerp-
po
is used to generate an on-time pulse via the PPO BNC. Multiple instances of this command can
be running for different pulse output times, allowing scheduling of multiple triggers.
The format of the command is:
triggerppo = X hh:mm:ss<CR>
Where:
X is the CPU I/O port of the PPO Option BNC (A,B,C,D,E or F).
hh:mm:ss is the UTC time-of-day for the trigger, with 1 second resolution.
<CR> is the ASCII carriage return character (0x0D).
An example is shown here:
Command:
triggerppo = A 13:50:00
This will cause a pulse on BNC A at
MeridianII reply:
OK
UTC time-of-day 13:50:00.
Trigger PPO Specifications
Rising edge on time, aligned with the desired second.
Accuracy < 10 nanoseconds RMS to UTC(USNO) when locked.
Pulse width mimics the standard 1PPS Output pulse width (20 us, 1 ms, 100 ms, or 500 ms).
Multiple trigger times must be at least 2 seconds apart.
Other PPO specifications are in Appendix K - Specifications, Optional Programmable Pulse Output
(CPU Module) .
Trigger PPO Operational Details
The
triggerppo
monitors the system time and compares it to the trigger time passed to it via the
console port interface. When the system time is about 1⁄2 second before the trigger time, then the
PPO is armed so that a single pulse occurs at the next second mark. When the system time is about a
1⁄2 second after the trigger time, then the PPO is disarmed. For other details, at the console port type: