EndRun Meridian II, User Manual

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M e r i d i a n I I U s e r M a n u a l 100
C H A P T E R T E N
101 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
Serial I/O Port
This DB9M connector provides the RS-232 serial I/O console interface to Meridian II. This console
allows you to initialize and maintain Meridian II. See Chapter 3 - Console Port Control and Status
for more information. See Appendix K - Specifications, Serial Port I/O for pinout.
1 PPS Output
The 1 PPS Output shown in the drawing above as “B-1 PPS” is a standard TTL output on Meridian
II. There are optional 1 PPS signals such as: 1 PPS (RS-422), and Inverted 1 PPS. The Program-
mable Pulse Output also has a 1 PPS and Inverted 1 PPS selection.
The pulse width is normally 1 millisecond wide when shipped from the factory but can be changed
(see below). For details on the 1 PPS signal definition see Appendix K - Specifications, 1 PPS Out-
put .
View the 1 PPS Connector
On the front-panel display traverse to the Main Menu and then to CPU_I/O. This display lists any
connector on the CPU Module that has an optional I/O signal. Connectors are identified as A, B or C.
Select the particular connector (I/O-A, I/O-B or I/O-C) to see which signal is installed.
Or, you can use this console port command:
Command:
cpuio
MeridianII reply:
CPU I/O B - 1 PPS OUTPUT is Installed
Current Setting = (See systemio command)
Change the 1 PPS Pulse Width
On the front-panel display traverse to the Main Menu and then to Sys_I/O. There will be a selection
for 1 PPS_Out. Select this and you will be able to choose from among these pulse widths: 20 micro-
seconds, 1 millisecond, 100 milliseconds and 500 milliseconds.
Or, you can use these console port commands:
Command:
systemio
MeridianII reply:
System I/O Signal 1 PPS OUTPUT is Installed
Current Setting = 1 Milliseconds Pulse Width
Command:
systemioconfig
MeridianII reply: Interactive script is started so you can change the pulse width.
The 1 PPS is a “system signal”. This means that there is one 1 PPS signal that affects the whole sys-
tem. In other words, if your Meridian II has multiple 1 PPS outputs and you change the pulse width,
then all 1 PPS outputs will be affected.