Appendix E
Indicators/Switches and Connectors
Indicators
Figure E-1. MultiMux Front Panel
Table E-1. LED Indicators
Indicator
Description
Channel
XMT/RCV
The Channel Transmit (XMT) and Receive (RCV) indicators show the activity level on each channel.
MultiMux MMV1608 uses Channel One through Channel Eight indicators, MMV1616 uses
Channel One through 16, MMV3224 uses Channel One through Channel 24, and finally
MMV3232 uses Channel One through 32.
FC
The Flow Control (FC) indicator is On when the MultiMux has stopped the channel data, because the
channel cannot accept any more data. If the channel data is being stopped by a remote
device, the FC indicator on the host MultiMux lights. The Flow Control Received (FCR)
indicator on the affected composite link also lights. If the channel data is being stopped by one
of the composite links, only the FC indicator for the affected channel lights.
Table E-1. LED Indicators (Continued)
Indicator
Description
Composite Link A/B
CD
The Carrier Detect (CD) indicator lights when the composite link detects a carrier signal from the
remote MultiMux. The CD indicator lights when a carrier signal is detected for an internal DSU
and when an external device (DSU or composite link modem) is connected to the composite
link, and is detecting a valid carrier.
RCV
The Receive (RCV) indicator flashes as data is being received from the remote multiplexer.
The RCV indidator flashes for both internal DSU and an external link device.
XMT
The Transmit (XMT) indicator flashes as data is being transmitted to the remote multiplexer.
The XMT indicator flashes for both internal DSU and an external link device.
CTS
The Clear To Send (CTS) indicator lights when the composite link is ready to transmit data.
The CTS indicator lights for both internal DSU and an external link device.
RXT
The Retransmit (RXT) indicator lights when the local MultiMux has received a request to
retransmit a block of data and is retransmitting that block. The RXT indicator lights for both
internal DSU and an external link device.