I/O Discrete (Module K6 Ver. 4)68C3 Operations Manual North Atlantic Industries, Inc. 12/19/2014Rev: 2014-12-19-0947 www.naii.com Page 172 of 330Input/Output FormatEach individual channel may be programmed for either input or output. Channel configuration is programmed ingroups of 8. Write integer 0 for input; 1, 2 or 3 for specific output format.REGISTER D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 FUNCTIONInput/OutputT Ch. 01-08 Ch.08 Ch.07 Ch.06 Ch.05 Ch.04 Ch.03 Ch.02 Ch.01 ChannelInput/OutputT Ch. 09-16 Ch.16 Ch.15 Ch.14 Ch.13 Ch.12 Ch.11 Ch.10 Ch.09 ChannelInput/Output DH DL DH DL DH DL DH DL DH DL DH DL DH DL DH DL D=DATA BITInteger DH DL0 0 0 Input1 0 1 Output, Low-side switched, with/without current pull up2 1 0 Output, High-side switched, with/without current pull down3 1 1 Output, push-pullInput/Output InterfaceThe Input/Output (I/O) Interface can be configured in a variety of ways. A pair of drive FETs and current circuitsare provided at each I/O pin. See I/O interface diagram below.Output: When configured as an output, the interface can act as a “High-Side”, “Low-Side” or “Push-Pull” drive,providing up to 500ma per channel or 1A when two channels are connected in parallel. The total output permodule (16 channels) cannot exceed 8.0 amps (Maximum source current ‘rules’ for rear I/O connectors still apply – see generalspecifications).Input: When configured as an input, output drivers are disabled. I/O interface can act as a current source, currentsink or voltage sensing circuit. For contact sensing, set each channel for pull-up or pull-down using the Pull-Up/Down Current Configuration register and enter the appropriate current level in the Current For Sink/Sourceregister. Define contact closure and hysteresis using Upper and Lower Threshold. See Read I/O register to readinput signal logic state. No additional resistors or hardware is required to provide for current flow. A current valueof zero disables the current source/sink circuits and configures for voltage sensing. Default is voltage sensing.Level or contact sensing can be mixed within a channel bank, if the contact sensing channels are externally pulledup or pulled down. If this module supplies the current for the contact sensing, then level and contact sensingcannot be mixed within a channel bank.All four threshold levels must be programmed. For input, threshold levels define logic state. For output, thresholdlevels are used in BIT test (wrap-around) signal monitoring.Voltage Sensing Circuitdefined by Threshold valuesInput/OutputI/O PinEnableEnableDriveDriveOUTPUT CONFIGURATIONS INPUT CONFIGURATIONSINPUT/OUTPUT INTERFACE0 to 5 ma0 is OFF0 to 5 ma0 is OFFVCCVCCVCCI/O PinI/O Pin0.5 mARECOMMENDED CIRCUITto detect OPEN WireAdd 10k Ohm resister, nearest toload, just before contact switch.Source 0.5 mA current.Threshold input levels accordingly.VCCI/O PinZin 10kLOADLOADZinHigh Side DriveCurrent SourceLow Side DriveOpen CollectCurrent SinkVoltage Sensing Circuitdefined by Threshold valuesInput/OutputI/O PinZin"Voltage Sensing"VCCPull-downCurrent“Contact Sensing”Switch ClosureI/O PinI/O PinPull-up CurrentVCCZinZinZinVCCI/O PinZinPush-Pull DriveLOADVCCLOADNote:Zin = 1 mΩFig 1 Fig 2 Fig 3
