NI 60xxE, NI 62xx, and NI 63xx (formerly E Series, M Series and X Series, respectively) Multifunction I/O DAQ modules and devices represent three generations of NI DAQ products.  Each successive release (60xxE, 62xx, then 63xx) has provided a host of new features which are outlined below. This document is only intended a summary of the features. Please review NI DAQ manuals and specifications for more detailed information. 

Note: Most E Series devices have a 60xxE model number, most M Series devices have a 62xx model number, and most X Series devices have a 63xx model number, where xx can be any number. Examples for E Series, M Series and X Series: NI 6052E, NI 6251 and NI 6361, respectively. 

* Available on some devices 
**Digital I/O subsystem does not have its own internal clock source, and therefore, an external signal or clock from another subsystem on the board must be provided. See Correlated DIO with USB M Series DAQ Device for additional details.

Note: this is not intended to be a comprehensive list of all differences.

• Dedicated sample clocks for digital I/O tasks
• All tasks are retriggerable.  On M Series this is only true for counter tasks
• 4 Counters with advanced features (refer to the X Series User Manual for more information)
• 100 MHz timebase available for all tasks (M Series uses 80 MHz for counters and 20 MHz for analog tasks)
• Simultaneous sampling available on some boards
• Higher throughput for streaming over PCIe and PXIe busses

Note: this is not intended to be a comprehensive list of all differences.

• Much larger analog input and output FIFO buffers
• 4 or 6 DMA channels, which increase performance when performing multiple tasks
• NI-TIO counter features suport, such as two-edge separation and quadrature encoding
• 16 PFI lines (M Series) vs. 10 PFI lines (E Series)
• Debouncing filters on the PFI and RTSI lines
• Better protection on the digital input and output and PFI lines
• AO offset support on Accuracy M Series boards
• On M Series devices, timing signals such as counter output, freqout, and sample clocks, can be exported to any PFI line. On an E Series device, these signals must be exported through their dedicated lines.
• E Series devices only have an AO internal reference of 10 V. For M Series, the Value boards have a reference of 10 V, the Performance boards have references of 5 and 10 V, and the Accuracy boards have references of 1, 2, 5, and 10 V.
• M Series PXI devices have the ability to phase lock to a common PXI backplane clock for easier and more accurate synchronization of measurements across multiple devices. E Series PXI devices do not have this functionality.

Note: this is not intended to be a comprehensive list of all differences.

• X Series and M Series are only supported with the NI-DAQmx driver, while E Series is supported in both Traditional NI-DAQ and NI-DAQmx.
• Unscaled data is not calibrated with M Series or X Series, while unscaled data for E Series is calibrated.
• For analog triggering, M Series and X Series use APFI0 and APFI1; E Series uses PFI0.
• Synchronization between devices is handled differently between devices.  E Series devices utilize a master timebase of 20 MHz (clocks are divided down from this).  M Series and X Series use a reference clock to PLL their own internal timebases to.
• Internal resistors on the PFI lines have changed between the E Series and X/M Series. The E Series devices have a ~50 kOhm pull up resistor connected internally to each PFI line, while the X/M series have a ~50kOhm pull down resistor.

Hardware and Connectivity

• Most M Series devices retain the same 68-pin format as E Series devices with all of the same signals mapped to the same pins, with the following exceptions:
  • PFI 0 on an E Series device serves as both an analog and a digital trigger input. M Series devices have their own dedicated analog trigger inputs, APFI 0 and APFI 1; PFI 0 only can accept digital signals.
  • The pin corresponding to PFI 15 on an M Series device corresponds to a digital ground on an E Series device.
• Some M Series devices have two 68-pin connectors. The first connector maps directly to the E Series pinout, with the exceptions listed above. The second connector is identical to the first, with the following exceptions:
  • AI <0..15> are replaced with AI <16..31>.
  • AO <0..1> are replaced with AO <2..3>.
  • DIO Port 0 lines <0..7> and Ports 1 and 2 (the 16 PFI lines) are replaced with Port 0 lines <8..31>.
• Although the E Series and M Series pinouts are the same, the connector styles are different. M Series devices use VHDCI connectors, the same connectors as PCMCIA E Series DAQCards. PCI and PXI E Series devices use SCSI connectors. Because the pin mappings are generally the same, E Series test systems usually do not have to be reconfigured or rewired to use M Series devices, though the cables will need to be replaced. The end of these M Series cables that connects to accessories uses an SCSI connector, and therefore can be used with all E Series accessories. Refer to the "Cabling Options for M Series" KnowledgeBase for more information on what cables can be used.
• If the M Series device has two 68-pin connectors, the first connector can be used with SCXI, SCC, and 5B signal conditioning control. Because the second connector does not contain PFI lines, it cannot be used with SCXI. The second connector can be used with the SCC and 5B signal conditioning options.

• X Series User Manual - DAQ X Series
• M Series User Manual - DAQ M Series
• E Series User Manual - DAQ E Series
• M Series Frequently Asked Questions
• What is NI X Series?
• Main Page : DAQ Multifunction I/O Cable and Accessory Compatibility
• PFI Lines (X Series. M Series, E Series)