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

When automatic gain is specified (RRR bits=000), the optimum gain (one of the sevenamplifier gains) is selected automatically, based upon the input signal voltage. Theselected gain can be returned to the program, along with the converted signal data, byissuing a read-ADC command. Since the indication of gain requires three bits, the inputdata itself is 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. Arinterruption request occurs at the end of the conversion cycle. The results of the cony 'rsionare then obtained by issuing a read-ADC, a read-ADC-extended-precision or aread-and-convert-ADC command.With either the read-ADC command or the read-and-convert-ADC command, the dataformat is in short form (12 bits plus sign) if automatic gain was specified, or in standardform (14 bits plus sign) if a particular range was specified. The read-ADC-extended-precisioncommand always returns the data in standard form.Convert Analog Input with External SynchronizationO 5 8 11 16 20 26 31Op code R Fun Zeros Mod DA MA00001 XX OO1000000001100100 XXXXXX1111 ii 11 1111 111 11111 11111swisl.,,,,..■■••••■■•••■,„■110.,....10.,,,..■••••••■■■•,,■,•••111....■•••••■••••■,••■•■•••••••••••,•••■•••••••■••■./....."O 8-F 2 0 1 9 0-3 XThis command functions in the same manner as the convert-analog-input command except thatthe start of conversion depends upon the receipt of an external synchronization input pulse.The user provides the external synchronization input pulse to start the analog-to-digitaldata conversion. (System/7 Installation-Manual—Physical Planning, Order No. GA34-0004,contains more detailed data on the external synchronization input pulse.)Read ADCO 5 8 11 16 20 26 31Op code R Fun Zeros Mod DA MA00001 XXX 010000000000100100 XXXXXX1i 11 it 11 1111 III 11111 11111O8-F 4 0 0 9 0-3 XThis command stores the binary output value from the ADC into the index register (R), orthe accumulator if R=000.IBM 5012 Multifunction Module Model Al 13-11