The ICEU VME Card Specifications

• Simulates all the digital interfaces of the ICM S-Band Transponder (SBT or Transponder)
• All simulated Transponder interfaces are optp isolated from VME ground 
• VMEbus interface for forward link data, 4096 words of buffering 
• Automatically inserts 32-bits of minimum idle data between commands 
• Programmable idle data, all 1's, all 0's, or alternating 1's and 0's 
• VMEbus inferface for correlated return link data, 32 frames of buffering 
• Return link data is appended with time tag and CRC is checked 
• VMEbus interface for Transponder Mode/Frequency command reception 
• VMEbus interface for Transponder Status generation 
• Provides interface between JSC test facilities and ISC flight equivalent units 
• Provides forward link data to TURFTS (Digital NRZ-M) 
• Provides forward link data to TURFTS (Analoge BPSK) 
• Receives return link data from TURFTS 
• Generates LC EPOCH signals 
• Drives forward link data and receives return link data over the umbilical cable during launch support 
• Interfaces to the ELSE Bus Protection Unit (ELSE-BPU), during launch support 
• Interfaces to the ELSE Ordinance Reset VME Card, during launch support