IBM System/7 Functional Characteristics - All about the IBM 1130 ...

Convert Analog Input0 5 8 11 16 20 26 31Op code R Fun Zeros Mod DA MA00001 XXX 0 01000000000100100 XXXXXX1111 it 11 1111 111 111 I 1 1111 IS•••••••■,,,MINI. •••■111,„....011..." •••••••••,./.11111,. •••••■••,■111111, ...•••••■,••••••■0 8-F 2 0 0 9 0-3 XThis command starts an analog-to-digital conversion cycle based upon control informationcontained in the index register (R), or the accumulator if R =000. The control informationword has the format:0 15Mpxr addr**XX* R RROX XXXXXX1111 11 1 1 1 1 1 1S■1111.NeMer, ,•••■•••■,■,0-2 0-7 0-7 XHigh-order bits of multiplexeraddress field are in bits 2-3 ofthe control word.The range bits (RRR) in the control word specify the input voltage range and the amplifiergain desired, as shown in the following table.RRR Bits Input Voltage Range Amplifier Gain000 Automatic gain001 +10 mV 512010 +20 mV 256011 +40 mV 128100 +80 mV 64101 +160 mV 32110 +640 mV 8111 +5.12V 1When automatic gain is specified (RRR bits =000), the optimum gain (one of the sevenamplifier gains) is selected automatically, based upon the input signal voltage. The selectedgain can be returned to the program, along with the converted signal data, by issuing aread-ADC command. Since the indication of gain requires three bits, the input data itselfis reduced to 12 bits plus sign.The range bits (RRR) have no significance if the high-level amplifier is installed.This convert-analog-input command starts an analog-to-digital conversion cycle of theanalog input point specified by the multiplexer address field in the control word. Aninterruption request occurs at the end of the conversion cycle. The results of the conversionare then obtained by issuing a read-ADC or read-ADC-extended-precision command.With the read-ADC command, the data format is in short form (12 bits plus sign) ifautomatic gain was specified, or in standard form (14 bits plus sign) if a programmed rangewas specified. The read-ADC-extended-precision command always returns the data instandard form.The multiplexer address field in the control word consists of bits 2-3 (the fieldhigh-order bits) and 9-15. The nine bits can be considered as a binary field to encodeaddresses 000 to 383. Bit 8 is reserved and set to zero. Bits 2-3 are necessary because ananalog input configuration (models B 1/E2/E2) can have up to 384 points.IBM 5014 Analog Input Module Models B1 and E2 10-3