GatesAir Intraplex DS-64NC, Installation And Operation Manual

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DS-64NC Synchronous Data Module 2 – Functional Description
Version 9.1
2-4 GatesAir
Intraplex Products
2.4.3 Remote Loopback
A remote loopback also turns receive-side data around to the transmit side at the line interface. Use
this loopback to check out the data transmission link. Activating a local equipment loopback is
equivalent to the far end shelf requesting a far end loopback; that is, a local equipment loopback
returns the receive data signal back to the far end of the circuit.
You can also initiate a remote loopback at one end to check out the DS-64NC module at the other end.
Activating the remote loopback at the near end (Location 1 in Figure 2-2) causes a loopback in the
DS-64NC module at the far end (Location 2). Activation and deactivation of the remote equipment
loopback is implemented in-band by replacing the payload data with fixed loop-up and loop-down
signals, respectively. As in the case of the equipment loopback, if the backplane buses in the shelf are
not frequency-locked when the remote loopback is in effect, the transmit-side FIFO spills periodically.
2.5 Diagnostics
2.5.1 Test Pattern Generator
The module includes test-pattern generators on both the transmit and receive sides, along with a
synchronizer on the receive side. The payload may be replaced with a test pattern for diagnostic
purposes, either in a one-way end-to-end mode or a loopback mode.
A front-panel indicator light shows bit errors, which are accumulated in a performance register
(Section 3 – Installation Configuration). Section 2.7.4 – Test Pattern Generator Setup gives test
pattern settings.
2.5.2 Performance Registers
The DS-64NC module maintains performance registers that keep track of seven conditions and event
histories:
●
Current transmit-side FIFO depth
● Transmit-side FIFO underrun count since last reset
● Transmit-side FIFO overrun count since last reset
● Current receive-side FIFO depth
● Receive-side FIFO underrun count since last reset
● Receive-side FIFO overrun count since last reset
● Receive-side bit error count since last reset
These registers can be read and reset via the remote port on the multiplexer, using P codes and S
codes with the Intraplex Simple Command Language (ISiCL). Section 2.8.2 gives details on these
codes. The multiplexer operation manual gives a fuller description of ISiCL.
2.6 Alerts and Alarms
This section discusses conditions which cause the DS-64NC module to report ALERT and ALARM
signals to the shelf common module.
2.6.1 Alerts
There are two types of alerts:
●
Configuration error
This error indicates that you have selected a combination of data rate and starting time slot that
does not permit all data to fit into the time slots available, given the current settings for system
usage (T1 or 2 MB) and payload bits per time slot (56 or 64).