Digital I/O - Differential Transceiver


Digital I/O - Differential Transceiver

NAI’s latest generation Differential I/O Multi-Mode Transceiver Modules are used on our rugged COTS Multifunction Embedded I/O Boards, Single Board Computers (SBCs), and Configurable Systems offered in OpenVPX, cPCI, VME, and PCI/PCIe configurations.

Both modules are offered in two versions: the Standard Functionality (SF) module (DF1) and the Enhanced Functionality (EF) module (DF2). Both modules feature 16 individual RS422/RS485 I/O channels that are programmable for either input or output, and include extensive diagnostics.

Our Smart Function Modules provide uniquely flexible, mix & match customization options for use with our COTS hardware. Learn More

Modules DF1 – DF2

Function modules DF1 and DF2 (Enhanced Version) are multi-mode transceivers with 16 programmable I/O channels. Differential transceivers increase resistance to noise by creating two complementary signals. These complementary signals produced on balanced lines double noise immunity by creating lower power requirements due to lower supply voltages.

When programmed for input, each differential channel has a selectable internal resistor (120 ohm) across its inputs. Each channel also can be programmed for fast or slow slew rates (a slow slew rate may be desirable for certain sensitive EMI-radiated transmission line applications). Status and/or interrupts can be polled/enabled for each channel to indicate transition on rising edge, transition on falling edge, or Background Built-in-Test (BIT) fault. Debounce circuits for each channel offer a programmable time delay to eliminate false signals resulting from contact bounce commonly experienced with mechanical relays and switches. All inputs are continuously scanned.

Continuous Background Built-in-Test (BIT) status provides real-time channel health for mission-critical systems. This feature runs in the background and is transparent in normal operations. When the channels are programmed as inputs, a redundant, read-back circuit continually scans each channel to verify the input. When the channels are programmed as outputs, the read-back circuit is compared with the commanded output logic.

DF1/DF2 Block Diagram

Enhanced Functionality Module DF2 Features

  • 16 channels available as inputs or outputs
  • Programmable Pulse Width Modulation (PWM) output mode
  • Pattern Generator output mode
  • Programmable for fast or slow slew rates
  • Programmable debounce circuitry with selectable time delay eliminates false signals resulting from relay contact bounce
  • Built-in test runs in background constantly monitoring system health for each channel


Click below for manuals and specifications:

DF1Sixteen Differential I/O Multi-Mode Transceiver ChannelsN/AModule Manual - DF1
DF2Enhanced Sixteen Differential I/O Multi-Mode Transceiver ChannelsN/AModule Manual - DF2

Function module(s) featured in products below:

ModelBoard TypeBoard ArchitectureFunction Module SlotsSizeEthernetMaster / SlaveOn Board ReferenceOther
75G53U cPCIARM / Xilinx® Zynq3 2 x GbBoth   
64G5VMEARM / Xilinx® Zynq6 2 x GbBoth YUser application ARM processor capability
68G53U OpenVPXDual Core ARM® Cortex® A9 @ 800 MHz3 2 x GbBoth  Slot profile: SLT3-PER-1U-14.3.3 / Module profile: MOD3-PER-1U-16.3.3-2
79G5PCIe 31/2   N/A 
ModelBoard TypeProcessorFunction Module SlotsMaximum MemoryMaximum StorageVideo OptionsEthernetAvailable O/S
75ARM13U cPCI SBCXilinx® Zynq 7015 with Dual Core ARM® Cortex® A9 @ 800 MHz3512 MB DDR3L SDRAM32 GB SATAII NAND FlashN/A2 x GbWind River® VxWorks®, Xilinx® PetaLinux OS and DDC-I Deos™ support
75PPC13U cPCI SBCNXP® QorIQ® P2041 Quad-Core e500mc Processor @ 1.2 GHz28 GB DDR3L SDRAM32 GB SATAII NAND FlashN/A2 x GbWind River® VxWorks®
75INT23U cPCI SBCDual Core Intel® i7 3517UE @ 1.5 GHz28 GB DDR3L SDRAM32 GB SATAII NAND FlashVGA, HDMI, LVDS, or DVI2 x GbCentOS, Red Hat®, Linux®, and Windows® Embedded Standard 7
64ARM16U VME SBCXilinx® Zynq Dual Core ARM® Cortex® A9 @ 800 MHz6 + AC Ref512 MB DDR3L SDRAM32 GB SATAII NAND FlashN/A2 x GbWind River® VxWorks® and Xilinx® PetaLinux OS support
68PPC23U OpenVPX SBCNXP® QorIQ® T2080 Quad Core @1.5 GHz2 8 GB DDR3 SDRAM32 GB SATAII NAND FlashN/A2 x GbWind River® VxWorks®
ModelPhotoBoard TypeDimensions w/Connectors (w x h x d)Volume w/Connectors (in3)Weight / lbs (fully populated)Est. Typ. Power Dissipation (W)# of Board SlotsFunction Module SlotsMax I/O PinsEthernet
NIU1AModule6.8" x 1.5" x 2.5"28.90<1.25 to 15 WN/A1592 x Gb
NIU2AModule7.0" x 3.0" x 2.5"52.5<2.755 to 25 WN/A21322 x Gb
SIU313U4.71" x 2.35" x 8.71"96.41<5.07 to 35 W131322 x Gb
SIU333U4.71" x 4.78" x 8.71"196.10<10.014 to 75 W393222 x Gb
SIU353U7.13" x 4.78" x 8.71"296.85<15.025 to 100 W5155122 x Gb