OnSite Series Getting Started Guide
Engineering Orderwire (EOW)
If the system is equipped with the factory-installed AUX (auxiliary) board, you can use AUX port 1 (AUX 1)
for voice communications between two or more interconnected OnSite OS-10 Series systems.
Figure 20
shows the location of EOW port (AUX 1) on the system. The port is located on the right side of the
chassis, at the back.
Figure 20. Location of EOW port (AUX 1) on OS-10 Series Chassis
The EOW port supports a 2-wire analog interface (tip and ring) with a nominal impedance of 900-ohm and
A-law PCM voice encoding. The system carries the PCM-encoded 64 kbit/s voice channel in either the E1 or
E2 byte of the STM-1 section overheard (SOH).
As a Foreign eXchange Station (FXS) interface, the EOW port supports the following functions:
•
Dial tone
•
Battery current
•
Ring voltage
The system uses an RJ-11 connector for the EOW port (AUX 1) but only two pins are used for the 2-wire con-
nection: pin 2 (tip) and pin 3 (ring), as shown in
Note
Engineering Orderwire (EOW)
The "tip" is the ground side and the "ring" is the battery side of the 2-
wire telephone circuit.
Figure
21.
4 • System Management Access
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