Chapter 5: Operating Instructions
Configure
Part No. 24001157
VersaMux-4000 Operation & Installation Guide
Page 5-13
Revision C
NOTE:
The External Clock Input requires a timing signal accuracy of +/- 50 ppm from the
nominal value.CV-2048 and CV-8448 internal oscillators have a specified accuracy
of +/-100 ppm while the VersaMux has a tracking tolerance of +/-50 ppm.
Therefore, when connecting a VersaMux to a CV-2048 or CV-8448 do not use the
CV-2048 or CV-8448 internal oscillators as a timing reference for the system.
Ext-Clk-Type Parameter
The
Ext-Clk-Type
parameter specifies the type of signal presented to the Ext-Clk
BNC connector (For more information about the External Clock Input, see
You need to set the
Ext-Clk-Type
parameter if the
Clk-Ref
parameter is set to
Ext-
1MHz
,
Ext-5MHz
, or
Ext-10MHz
provides descriptions of the
Ext-Clk-
Type
options.
Port-2
The VersaMux uses the recovered timing signal from the Port 2 interface to generate
the System Timing Clock Reference.
Port-3
The VersaMux uses the recovered timing signal from the Port 3 interface to generate
the System Timing Clock Reference.
Port-4
The VersaMux uses the recovered timing signal from the Port 4 interface to generate
the System Timing Clock Reference.
Internal
Internal mode bases system timing off of an on-board oscillator with a frequency
accuracy of better than +/- 20 ppm.
Table 5-2
Clk-Ref Option Descriptions
Option
Description
Table 5-2
(page 2 of 2)
Table 5-3
Ext-Clk-Type Option Descriptions
Option
Description
RS-422
Use this option for a RS-422 clock (the impedance between the A and B leads is 100-
ohms).
Zero-Crossing
Use this option for a station clock (1.0 MHz or 5.0 MHz) which provides a sine wave
(1V RMS minimum and 2V RMS maximum). If the external input is single ended (center
lead only), then the impedance of the external input is 50-ohms (assuming a common
ground between the Versamux and the external clock source).
TTL
Use this option for a digital TTL (Transistor-Transistor Logic) clock input.The Station
Clock Interface input impedance is 50 +/-10% to ground in TTL mode.
