Measurement Computing USB-2627 - Manual (Page 22)

USB-2627 User's Guide Specifications
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Note 3: The DAC update rate is not affected by the number of channels in the scan.
Table 6. Calibrated absolute accuracy specifications
Range Absolute accuracy (±LSB)
±10 V 16.0
Table 7. Calibrated absolute accuracy components specifications
Range % of reading Offset
(±mV) Offset tempco
(µV/°C) Gain tempco
(ppm of range/°C)
±10 V ±0.0183 1.831 12.7 13
Table 8. Relative accuracy specifications (±LSB)
Range Relative accuracy (INL)
±10 V 4.0 typ
Analog input/output calibration
Table 9. Analog input/output calibration specifications
Parameter Specification
Recommended warm-up time 15 minutes min
Calibration method Self-calibration (firmware)
Calibration interval 1 year (factory calibration)
AI calibration reference +5 V, ±2.5 mV max. Actual measured values stored in EEPROM.
Tempco: 5 ppm/°C max
Long term stability: 15 ppm/1,000 hours
AO calibration procedure The analog output pins are internally routed to the analog input circuit.
For best calibration results, disconnect any XDACx connections at the I/O connectors
prior to performing AOUT calibration.
Digital input/output
Table 10. Digital input/output specifications
Parameter Specification
Digital type TTL
Number of I/O 24
Configuration Three banks of 8. Each bit may be configured as input (power on default) or output.
Pull-up configuration Each port has 47 kΩ resistors that are configurable as pull-up or pull-down (default)
using an onboard jumper (W5, W6, W7).
Digital I/O transfer rate
(system-paced, asynchronous) 33 to 4,000 port reads/writes or single bit reads/writes per second typ;
system dependent.
Input high voltage 2.0 V min
5.0 V absolute max
Input low voltage 0.8 V max
0 V recommended min
Output high voltage 4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –24 mA)
Output low voltage 0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 24 mA)
Output current 60 mA max, not to exceed 24 mA for one bit, resulting in 2.5 mA max when all 24 bits
are enabled.