The V450 is a 16-channel 24-bit VME isolated analog-to-digital converter module which can acquire a wide range of DC voltages, including thermocouple readings with automatic cold junction compensation. Each channel is independently isolated with it's own A/D converter, signal conditioning, input protection circuits, and test relay.
All data I/O is managed through a transparent, VMEbus-speed dual-port memory. Conversions are continuously available with no need for handshaking; provisions are available for synchronized simultaneous data acquisition.
Programmable parameters such as voltage input range, thermocouple type, and sample rate, and data acquisition results and status flags are accessible in per-channel VME registers. Independently programmable digital filters and optional plug-in analog front-end filters simplify data-acquisition systems on both software and hardware sides.
Thermocouple channels can be individually programmed to work with any of four external RTD reference junctions, or thermocouple wire can be brought directly into the front panel D25 connectors and referenced to the on-board temperature sensor. Cold-junction compensation uses high-density table lookups rather than straight line approximations, and all reference junction temperatures are readable at any time.
FUNCTION | 16-channel isolated voltage/thermocouple input |
DEVICE TYPE | 16-bit VME register-based slave: A24:A16:D16 Implements 256 16-bit registers at switch selectable addresses in the VME 16 or 24 bit addressing spaces |
CHANNELS | 16, programmable functions, galvanically isolated |
RANGES | Programmable per channel Voltage: 14 bipolar ranges, ±25 mV, 50 mV, 80 mV, 125 mV, 250 mV, 500 mV, 1.25 V, 2.5 V, 5 V, 12.5 V, 25 V, 50 V, 125 V, 250 V Thermocouples: Types J K E T R S B N |
RESOLUTION | Voltage mode, 24 bits Temperature mode, 0.0625°C |
SAMPLE RATE | Programmable per channel, 4 to 500 readings/second Default rate of 16/second rejects 50/60 Hz noise |
OFFSET ERROR (0-60°C) | Range > 20V: ± 10 ppm range ± 250 µV 1V < Range < 20V: ± 10 ppm range ± 20 µV Range < 1V: ± 10 ppm range ± 2 µV |
OFFSET ERROR (-40-80°C) | Range > 20V: ± 15 ppm range ± 1000 µV 1V < Range < 20V: ± 15 ppm range ± 50 µV Range < 1V: ± 15 ppm range ± 5 µV |
GAIN ERROR | (15-35°C) ± 300 ppm of measurement ± 30 ppm/°C outside this range |
INPUT IMPEDANCE | Range < 1 V: 100 MΩ min Range > 1 V: 1 MΩ min |
PROTECTION | ±350 volts differential ±750 volts common-mode ESD to 15 KV, human body model |
NOISE REJECTION | > 80 dB rejection of 50/60 Hz noise at default sample rate of 16.7/second |
RTD INPUTS | Four non-isolated external reference junction inputs for 4-wire platinum RTD sensor, 100 Ω or 1 kΩ, ISO "385" curve Protected against shorts, ESD |
ONBOARD SENSOR | Semiconductor reference junction temperature sensor, ±2°C typical accuracy |
OPERATING TEMPERATURE | 0 to 60°C; extended -40 to 80°C MIL/COTS range available |
CALIBRATION INTERVAL | One year |
POWER | Standard VME supplies: +5 V, 1.0 A max +12 V, 5 mA max -12 V, 5 mA max |
CONNECTORS |
2 D25 female for channels and RTDs D9 male for test |
INDICATORS | LEDs indicate VME access, CPU activity, error conditions Additional user programmable LED |
PACKAGING | 6U single-wide VME module |
CONFORMANCE | ANSI/VITA 1-1994 (R2002) VMEbus spec; does not support byte writes Thermocouple tables based on NIST/ITS-90 RTD tables per IEC-751 for "385" curve RTDs |
Block Diagram: V450 analog/thermocouple input module
V450-1: 16-channel VME analog input module
V450-2: 16-channel VME analog input module with BIST
V450-151: 16-channel VME analog input module with pre-installed V451-50 50 Hz 6-pole analog bessel filter option
V450-181: 16-channel VME analog input module with pre-installed V451-80 200 Hz 6-pole analog bessel filter option
V450-251: 16-channel VME analog input module with BIST and pre-installed V451-50 50 Hz 6-pole analog bessel filter option
V450-281: 16-channel VME analog input module with BIST and pre-installed V451-80 200 Hz 6-pole analog bessel filter option
J470: 8-channel D25 female isothermal termination box
J475-1: 8-channel D25 female Din rail termination panel
J475-2: 8-channel D25 female Din rail termination panel w/ reference junction sensor
J55: 6' shielded D25 male to D25 male cable
J56: 10' shielded D25 male to D25 male cable
J71: Dual D9 female to Agilent 34104A cable
J75-1: D9 female to two(2) dual banana plug cable
V451-50: V450 Plug-In Filter, 50 Hz Bessel version (factory installation only)
V451-80: V450 Plug-In Filter, 200 Hz Bessel version (factory installation only)