Specifications
FOM-40 Installation and Operation Manual  Chapter 1 Introduction 
  Physical Description  1-3 
Diagnostics 
FOM-40 features RLB and LLB diagnostics for performing local analog and digital 
loopbacks and remote digital loopback. The local analog and remote digital 
loopbacks are controlled by front-panel pushbuttons or by a DTE interface for 
V.24, V.35 and RS-530 protocols. 
A front panel pushbutton generates an internal 511-bit pseudo-random test 
pattern (PATT), according to ITU V.52, for direct end-to-end integrity testing. 
When the test is running, the ERR indicator blinks for each bit error detected. 
1.2 Physical Description 
FOM-40 is available as a standalone unit or as a rack-mount card for the 
ASM-MN-214 hub. Figure 1-3 shows a FOM-40 standalone unit. 
Figure 1-3. FOM-40 Standalone Unit 
Seven front panel LEDs display the status of power, data flow, control signals, and 
diagnostics. Four front-panel pushbuttons activate three loopbacks and BER 
testing. For a detailed description of the front panel, see Chapter 3. 
The back panel includes a power connector (AC or DC), a DTE interface 
connector, and a line connector. The FOM-40 rear panel is described in 
Chapter 2. 
DIP switches can be configured to support a variety of modes for operating the 
modem. Refer FOM-40 Dip Switches on page 4-2 for DIP switch settings. 










