Chapter 1: Overview 5Meridian Link Release 5C/CCR Release 3C Diagnostic and Maintenance Guide• MVME167-03 SBC cardThe main CPU card of the Application Module. There are eight LEDsand two switches on the faceplate of the SBC card:— The red LED (Fail indicator) is lit when the BRDFAIL bit is set orwhen a watchdog time-out occurs. It is normal for this indicator toflicker while diagnostics are running; when a failure occurs, thisindicator is steadily lit.— The yellow LED (Status indicator) is lit when the MC68040STATUS pin is low (when steadily lit, it indicates that the processorhas stopped).— The green LED (Run indicator) is lit when the microprocessorexecutes a bus cycle.— The green LED (SCON indicator) is lit to indicate that the SBCcard is the VME bus system controller.— The green LED (LAN indicator) is lit when the LAN chip is thelocal bus master.— The green LED (+12V indicator) is lit when power is available tothe transceiver interface.— The green LED (SCSI indicator) is lit when the SCSI chip is thelocal bus master.— The green LED (VME indicator) is lit when the board is using theVME bus, or when the board is accessed by the VME bus.— The ABORT switch stops program execution and returns control tothe debugger.— The RESET switch, when enabled, generates a local reset. Thisswitch also generates a VME bus system reset.• MVME333-2 X.25 Communication Controller (XCC) cardThis card supports synchronous communications links to a hostcomputer and the Meridian 1. On the faceplate, there is a single redLED (Fail indicator), which lights when a hardware or LAPB/X.25communication software error occurs.
