777810-01 NI | Alldatasheet

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Technical content

Features

You can use the 24 optically isolated inputs of the NI 6527 devices to read the status of external logic at TTL and non-TTL levels. Each input channel has two differential isolated terminals – one for the signal and one for its reference. A potential difference of 2 to 28 VDC between the two terminals registers as a logic high. Logic low is between 0 and 1 V . The inputs feature 60 VDC isolation from the computer and between channels. Messaging – Change Notification NI 6527 devices can generate a message when one or more user- selected input lines changes, either from low to high, high to low, or both. Once notified of a change, NI-DAQ can read the status of other input lines, set outputs, or perform some other programmed operation. Using this feature, you can monitor lines without polling, thus using your CPU more efficiently. Debouncing Filter for Glitch Removal Each input line can be digitally filtered to prevent a momentary glitch or spike from affecting the line state. When you use messaging, filtering blocks spurious change events caused by noise on the input line. Digital Switch Outputs and Power-Up States The 24 solid-state relay outputs on the NI 6527 devices can switch external devices, including those requiring high input currents, and control digital logic levels at both TTL and non-TTL levels. Each relay output has two terminals. Writing a logic low to an output closes the connection between the terminals; writing a logic high opens the connection. Depending on how your load connects to the terminals, an output can either source or sink currents. By adding pull-up resistors externally and, if needed, an isolated power supply, you can output digital signals that source or sink currents. The solid- state relay outputs have a maximum switching capacity of 60 VDC, 30 V rms,o r 120 mA, and are isolated up to 60 VDC or 30 V rms from the computer and between channels. NI 6527 device outputs include circuitry to protect against transient currents above the rated values. When excessive current flows through the relay, the relay limits the current to approximately 260 mA (typical).

  • 24 optically isolated digital inputs (0-28 VDC)
  • 24 isolated, solid-state relay digital outputs (0-60 VDC, 0-30 Vrms)
  • Switch up to 120 mA
  • Digital filtering on inputs
  • Messaging (change notification)
  • NI-DAQ driver simplifies configuration and measurements Models
  • NI PCI-6527
  • NI PXI-6527 Operating Systems
  • Windows 2000/NT/XP
  • Real-time performance with LabVIEW (page 134)
  • Others such as Linux and Mac OS X (page 187) Recommended Software
  • LabVIEW
  • LabWindows/CVI
  • Measurement Studio Other Compatible Software
  • Visual Basic
  • C/C++, C# Driver Software (included)
  • NI-DAQ 7 NI 6527 Family Bus Digital I/O Lines Maximum Rate Logic Level Isolation Handshaking I/O 8255 chipset Change Notification Pattern Matching NI 6527 PCI, 24 inputs and Software timed O to 28 VDC input 60 VDC – – ✓ – PXI 24 outputs and 0 to 60 VDC channel to channel (30 Vrms) output

Table 1. Digital I/O Products Specifications Summary (See page 385 for detailed specifications.)

Digital I/O Connectivity and Signal Conditioning 381National Instruments • Tel: (800) 433-3488 • Fax: (512) 683-9300 • info@ni.com • ni.com Digital I/O Connectivity and Signal ConditioningData Acquisition and Signal Conditioning Cables, Connector Blocks, and Signal Conditioning Choose your Digital I/O cables, connector blocks, and signal conditioning in two easy steps. Step 1. Choose your connector block and cable. (see digital I/O accessories section for details) Step 2 (Optional). Choose your signal conditioning hardware and enclosures. Device Connector Block Cables PCI-6527, PXI-6527 CB-100 Kit Kit includes R1005050 cable SCB-100 SH100-100-F CA-1000, CB-50, CB-50LP R1005050 (splits into two 50-pin connectors); with this cable, you can use two accessories from this group with one NI 6527 device PCI-6503, PC-DIO-24 CA-1000, CB-50, CB-50LP SH50-50 or NB1 DAQCard-DIO-24 CA-1000, CB-50, CB-50LP PSH27-50F-D PCI-DIO-96, PXI-6508 CB-100 Kit Kit includes R1005050 cable SCB-100 SH100-100-F CA-1000, CB-50, CB-50LP NB5 (Splits into two 50-pin connectors); with this cable, you can use two accessories from this group with each device. PC-DIO-96 CB-100 Kit Kit includes NB5 cable SCB-100 SH100-100-F CA-1000, CB-50, CB-50LP NB5 (Splits into two 50-pin connectors); with this cable, you can use two accessories from this group with each device. SCXI Signal Conditioning SSR Series SC-206x Device ER-8, ER-16 CA-1000 Custom Device System (Page 270 ) Modules (Page 349 ) (Page 349) Electromechanical Relays (Page 349 ) Connectivity Enclosure (Page 351)

electromechanical relays, digital data buses, and more. operation in the LabVIEW Real-Time environment. of built-in channel-to-channel isolation between each I/O channel. hardware-timed NI 653x devices on page 432. 1Handshaking supplied by the 8255; only one handshaking mode is available. See page 376 for details. pages for more information. See page 376 for details. Table 2. Digital I/O Applications. Table 3. Digital I/O Signal Conditioning Accessories.

376 National Instruments • Tel: (800) 433-3488 • Fax: (512) 683-9300 • info@ni.com • ni.com Digital I/O OverviewData Acquisition and Signal Conditioning Digital I/O Overview Hardware-Timed Digital I/O Hardware-timed digital I/O, also referred to as high-speed digital I/O, implies that the writing and reading of digital lines is controlled by an external or internally generated clock signal. The clock signal latches the digital data into or out of a buffer, which can be streamed at high speed to the computer. With hardware-timed digital I/O, software commands are similar to buffered data acquisition command and an array of data is passed with each read or write operation. NI 653x devices can be used in either a hardware-timed or a software-timed manner. For more information on NI 653x devices see page 432. Handshaking Digital I/O Handshaking digital I/O refers to transfers of digital data between the digital I/O device and a peripheral. Both parties in the transfer control a handshaking line and can pause the operation if they are unable to keep up with the data rate. NI 650x devices offer

8255 Mode 2 bidirectional transfers at typical constant sustainable

rates of 1 to 10 kbytes/s using a 233 MHz Pentium computer. For more information on high-speed handshaking, see the NI 653x devices on page 432. Power-Up States Some applications require that the digital I/O device power up with a determined value on the data lines. This procedure ensures that equipment connected to the digital I/O device is not damaged during the time after power is applied and before the software application begins running. All NI digital I/O devices power up with a known state on the digital I/O lines, either logic high, logic low, or high impedance. NI 6527 devices offer software programmable power-up states on each line that can be configured using a software utility located in the Developer Zone. For more information, visit ni.com/info and enter ex95u3. Change Notification and Pattern Matching To monitor digital lines without continuously polling their state, you can use Change Notification on NI 6527 devices to notify your application when one or more digital input lines changes from low to high, high to low, or both. Y ou can configure NI 650x devices to provide pattern matching when the input lines on a port match a specific pattern. In a PXI LabVIEW Real-Time application, change notification and pattern matching can be used to deterministically trigger execution for high-reliability real-time event response. NI offers a complete array of digital I/O products for connection to any digital data bus or device.