Model SR715 Model SR720 LCR Meters

REMOTE PROGRAMMINGSTATUS BYTE DEFINITIONSThe SR715/720 reports on its status by means of three status bytes: the serial poll byte, the standard statusbyte, and the LCR status byte.On power on the SR715/720 may either clear all of its status enable registers or maintain them in the statethey were in on power down. The action taken is set by the *PSC command and allows things such as SRQon power up .SERIAL POLL bit name usageSTATUS BYTE0 Ready The SR7XX is ready to perform a measurement.1 unused2 unused3 LCR An unmasked bit in the LCR status register has been set.4 MAV The gpib output queue is non-empty5 ESB An unmasked bit in the standard status byte has beenset.6 RQS/MSS SRQ (Service Request)bit.7 No Command There are no unexecuted commands in the inputqueueThe LCR and ESB bits are set whenever any unmasked bit in their respective status registers is set. A bit isunmasked by setting the corresponding bit in the corresponding enable register to 1. The Serial Poll Statusbits are not cleared until the condition which set the bit is cleared. Thus, these bits give a constant summary ofthe unmasked or enabled status bits. A service request will be generated whenever an unmasked bit in theSerial Poll register is set. Note that service requests are only produced when the bit is first set and thus anycondition will only produce one service request. Accordingly, if a service request is desired every time an eventoccurs the status bit must be cleared between events.For example, to generate a service request whenever an overrange condition occurs, bit 4 in the LCR StatusEnable register needs to be set. (SENA 16 command). When overrange occurs, bit 4 in the LCR Status Byteis set. Since bit 4 in the LCR Status Enable Register is set, this will also set bit 3 in the Serial Poll Status Byte.In order for this to generate a service request, bit 3 in the Serial Poll Enable Register must be set (*SRE 8command).4-10