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

A medium-power non-isolated digital output group provides 16 solid-state switches forswitching up to 52.8V dc and 450 ma. of user-supplied power.Analog OutputOne or two isolated analog output points can be accommodated within the multifunctionmodule. Each point provides a voltage output to user terminals.2790 ControlA single loop of the IBM 2790 Data Communication System can be attached to themultifunction module. Such an attachment allows the System/7 to act as system controllerto the 2790 devices (2791/2793 Area Stations, 2792 Remote Communications Controller,and 2795/2796/2797 Data Entry Units). Data enters the 2790 system from a card reader,badge reader, pulse counter, or key entry unit. Output data to the 2790 system is sent to2791 indicator lights or to a printer attached to either a 2791 or 2793 Area Station.COMMON I/O COMMANDSThree I/O commands are common to all functions in the multifunction module: readDSW, read ID, and read-ID-extension. In these three commands, the contents of the deviceaddress field are ignored, but the module address is determined by the physical locationof the multifunction module in 'the 5026 Enclosure. The read ID and read-ID-extensioncommands are described earlier in Chapter 4 under "Input/Output Instruction,"since these two commands apply to all I/O modules.Read DSW0 5 1 1 16 20 26 31Op code R Fun Zeros Mod00001XXX010000000111!III Ii 11 1111 111DA11111MAXXXXXX111110 8-F 4 0 7 0 0-3 XThe read DSW command stores the 16-bit device status word (DSW) associated with themultifunction module into the index register (R), or the accumulator if R=000. Executionof this command resets the bits in the DSW.Device Status Word (DSW): The 16 bits in the device status word are set as a result ofdetected error conditions occurring during the execution of an immediate command to theI/O module. The operating program is notified of these error conditions by returning conditioncode 1 to the processor. If other commands are attempted before resetting the DSWbits, condition code 1 continues to be returned to the program.The significant bits in the DSW and their meanings are:Significant Bits Meaning1 Command reject. The multifunction module cannot execute thecommand. (For example, an interruption-causing command issuedto the device when it is disabled for interruptions.)3 Open circuit. A digital input circuit breaker is open when the digitalinput subaddress was selected.14 Data check. The multifunction module has detected a parity errorinvolving data. The operation that caused this condition usually canbe retried successfully if the error condition is intermittent.15 Invalid device address. An immediate command was issued to a devicethat is not installed in the multifunction module.IBM 5012 Multifunction Module Model Al 13-3