3Com S24x, S27x, S26x installation manual Idl, Clk

DSU Input and Output Signaling

Other Reporting Differences

Signal	Description (continued)
CL	CSU Loopback
	When this signal is “L”, the DSU hardware is looping the remote
	connection's receive to transmit.
IDL	Idle
	An “H” on this signal tells the DSU hardware to send idle bipolar
	violations to the remote system.
CLK	Clock Mode
	The signal “H” denotes the use of the network clock. The DSU option
	provides the clock when this signal is “L”.

You can view these signals using the control terminal Monitor menu item on the Main menu.

Other differences in control terminal output are:

•Detailed Port Statistics— show DSU input and output signaling as well as note the installed DSU DIM

•Detailed Node Statistics— show DSU DIM position

Example ofFigure 3-3shows the Diagnostics menu. Use this menu to access the loopback Diagnostics Menu options described in the next section.

Node:	nodename	Address (blank)Date: ___________Time:__________
Menu:	Diagnostics	Path: (Main.12)

1.Local Loopback

2.V.54 Loopback 2

3.V.54 Loopback 3

4.Fatal Error Reports

5.Logged Alarms«

6.Startup Diagnostics

7.DSU Internal Loopback

8.DSU Internal and External Loopback

9.Start Delay Measurement

10.Stop Delay Measurement

11.Display Delay Summary

12.IP Ping

#Enter Selection:

Figure 3-3. Diagnostics Menu

PathBuilder S24x, 26x, and 27x Switch Hardware Installation 3-9