The V470 is a 6U VME module that provides sixteen independent, isolated analog outputs that may be user-programmed to operate as voltage outputs or thermocouple simulators. Users may write temperature or voltage values at VMEbus speed, and the microprocessor will transparently do all necessary calculations and update the channel electronics.
In thermocouple simulation mode, the V470 includes lookup tables for all common thermocouple types, allowing users to write the desired temperature directly to VME registers. Any channel can be associated with any of the reference junction sensors located in the external field-wiring termination panels, or can use the onboard sensor. Cold-junction compensation is via table lookup of thermocouple potential for the type currently selected. Reference junction temperatures are readable.
Two front-panel D-25 connectors interface to external analog devices. Each connector provides eight differential outputs and connections for two 4-wire RTDs. A D9 connector provides in-crate calibration check. Each isolated channel incorporates a software controlled DPDT relay that allows the channel output to be diverted to the test connector.
Up to four output channels may be series-connected to provide outputs up to ±50 volts.
An optional built-in-self-test (BIST) subsystem adds additional switching and an onboard ADC and firmware that allows the invocation of a full closed-loop test of all ranges of all 16 channels.
FUNCTION | 16-channel VME analog voltage output and thermocouple simulation module |
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; 10 bipolar voltage ranges: ±25 mV, 50 mV, 80 mV, 125 mV, 250 mV, 500 mV, 1.25 V, 2.5 V, 5 V, 12.5 V; Thermocouples: Types J K E T R S B N |
RESOLUTION | Voltage mode, 16 bits: 0.76 μV/LSB on 25 mV range; Temperature simulation mode, 0.0625°C |
OUTPUT IMPEDANCE | 0.25 Ω max |
OUTPUT CURRENT | 20 mA min into short circuit indefinitely |
OUTPUT LOADING | Stable for capacitive loads up to 2 µF |
OUTPUT PROTECTION | Differential, short or applied ±35 V DC or peak AC; Common-mode, ±750 V DC or peak AC; ESD to 15 KV, human body model |
RTD INPUTS | Four non-isolated thermocouple reference junction inputs, 100 R or 1 K 4-wire Pt 385 RTD sensor |
RTD ACCURACY | ±250 PPM, equiv to 0.0625°C, range -65 to +150°C |
INPUT PROTECTION | Shorts to ground, ESD |
ONBOARD SENSOR | Semiconductor reference junction temperature sensor, ±2°C typical accuracy |
OPERATING TEMPERATURE | 0 to 60°C; extended MIL/COTS ranges available |
CALIBRATION INTERVAL | One year |
POWER | Standard VME supplies: +5 V, 0.6 A max +12 V, 1 A 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 |
Error | TYPICAL | LIMIT 15-35°C | LIMIT 0-60°C | LIMIT -40-80°C |
---|---|---|---|---|
Offset | ±5µV ±30ppm of range |
±20µV ±175ppm of range |
±30µV ±300ppm of range |
±40µV ±400ppm of range |
Gain | ±50ppm of output | ±310ppm of output | ±660ppm of output | ±940ppm of output |
Block Diagram: V470 analog output/thermocouple simulator module
V470-1: 16-channel VME analog output and thermocouple simulator module
V470-2: 16-channel VME analog output and thermocouple simulator module with BIST
V470-12: 16-channel VME analog output and thermocouple simulator module with BIST and conformal coating
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