GPIB-PC Functions — Overview Section FourGPIB-PC User Manual 4-2 ©National Instruments Corp.Status WordAll functions return a status word containing information about the stateof the GPIB and the GPIB-PC. You should test for the conditionsreported in the status word to make decisions about continuedprocessing. The status word is returned in the variable IBSTA.The status word contains 16 bits, of which 14 are meaningful. A bitvalue of 1 indicates the corresponding condition is in effect. A bit valueof zero indicates the condition is not in effect.Table 4.1 lists the conditions and the bit position to be tested for thatcondition. Some bits are set only on device function calls (d); somebits are set only on board function calls (b); and some bits are set oneither type (db).Table 4.1 - Status Word LayoutMnemonics Bit Hex Function DescriptionPos. Value TypeERR 15 8000 db GPIB errorTIMO 14 4000 db Time limit exceededEND 13 2000 db END or EOS detectedSRQI 12 1000 b SRQ interrupt receivedRQS 11 800 d Device requestingserviceCMPL 8 100 db I/O completedLOK 7 80 b Lockout StateREM 6 40 b Remote StateCIC 5 20 b Controller-In-ChargeATN 4 10 b Attention is assertedTACS 3 8 b TalkerLACS 2 4 b ListenerDTAS 1 2 b Device Trigger StateDCAS 0 1 b Device Clear StateA description of each status word and its condition follows.
