The V420 is an 8-channel, isolated, programmable resistance simulator. It uses entirely solid-state simulation to eliminate transient errors associated with relay switching, and provide for monotonic resistance changes. Channels are individually programmable in four resistance ranges, from 5 ohms to 65.5K. Channels can operate from microvolts up to 35V / 50mA. Overload protection and channel error detection are included.
Any channel may be rerouted, under software control, to the front-panel calibration-check connector, allowing the board to be tested for calibration by a precision DVM without disturbing the connections to the equipment under test. The BIST option adds an onboard precision ohmmeter, allowing loopback checking and full automatic self-test. Optional external termination and bridge-completion boards are available.
FUNCTION | 8-channel VME isolated resistance simulator |
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 | 8, 2-wire or 4-wire, galvanically isolated |
RANGES | Standard resistance ranges: 5 Ω to 500 Ω 50 Ω to 5 kΩ 500 Ω to 50 kΩ 5 kΩ to 65 kΩ Extended resistance ranges: 5 kΩ to 1 MΩ Platinum RTD ranges: -125°C to 700°C 100 Ω Pt385 (α = .00385) -125°C to 700°C 1 kΩ Pt385 (α = .00385) -120°C to 950°C 100 Ω ITS-90 (α = .00393) -120°C to 950°C 1 kΩ ITS-90 (α = .00393) -120°C to 950°C 500Ω ITS-90 (α = .00393) Copper RTD ranges: -100°C to 260°C 10 Ω (α = .00427) |
OPERATING RANGE | ±35 V differential, ±50 mA DC or peak AC per channel |
PROTECTION | ±50 V differential ±750 V common-mode ESD to 5 kV, human body model |
RESOLUTION | Standard resistance ranges: Variable from 12-15 bits with higher resolution at the lower end of the range RTD ranges: 0.0625°C |
ACCURACY | ±0.1% typical (±1% max) of resistance setting ±0.25°C on RTD ranges DC offset error < 10 µV |
NON-LINEARITY | ±5 ppm/V ±25 ppm/W |
TEMPERATURE COEFFICIENT | ±20 ppm/°C |
OPERATING TEMPERATURE | 0 to 60°C; extended MIL/COTS ranges available |
CALIBRATION INTERVAL | 1 year |
POWER | Standard VME supplies: +5 V, 1 A max +12 V, 1 A max -12 V, 1 A max |
CONNECTORS | 2 D25 female for channels 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 IEC-751 for "385" curve platinum RTDs ITS-90 for "393" curve platinum RTDs |
V420-1: 8-channel VME isolated resistance simulator 0° to 60°C
V420-2: 8-channel VME isolated resistance simulator 0° to 60°C with BIST
V420-3: 8-channel VME isolated resistance simulator 20° to 80°C MIL/COTS with BIST and conformal coating