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

The 5013 Digital I/O Module Model Al groups the following functions within onephysical enclosure:• As many as 128 digital input points• As many as 64 digital output points• One 2790'Control for an IBM 2790 Data Communication SystemAny combination of the above functions can be installed in a single digital I/O module.Programming support, however, is provided for only four 2790 Controls in a System/7configuration (this includes any 2790 Controls in 5012 Multifunction Modules). With thesingle exception that all 2790 Controls must be located within the same 5026 Enclosure,the digital I/O modules can belocated in any or all of the I/O module positions withina 5026 Enclosure (location 00 in the 5026 is the processor module location).FUNCTIONAL DESCRIPTIONDigital InputAs many as 128 isolated and/or non-isolated digital input points can be accommodated,in eight groups of 16 points each. Isolated two-terminal inputs can be activated by eithercontact or voltage sources provided by the user's equipment.The first two digital input groups can each be provided with a special feature that permitsthem to interrupt the System/7 processor. A 16-point group is compared with a 16-bit reference register, and interruptions can be initiated on the basis of either an equal oran unequal comparison.A non-isolated digital input group provides 16 latching or non-latching points of contactsensing capability. A non-isolated group cannot, however, have the process interruptfeature.Digital OutputAs many as 64 isolated and/or non-isolated digital output points can be accommodated, infour groups of 16 points each. Each isolated group can use either of the two optional digitaloutput circuits available (medium-power group or contact group). These circuits aredescribed in more detail in the System17 Installation Manual—Physical Planning, Order No.GA34-0004.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.2790 ControlA single loop of the IBM 2790 Data Communication System can be attached to thedigital I/O 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 sentto 2791 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 digital I/0 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 digital I/0 module in the 5026 Enclosure. The read ID and read-ID-extensioncommands are described earlier in Chapter 4 under "Input/Output Instruction," sincethese two commands apply to all I/O modules.14-2 GA34-0003