IC697ALG230

Input Ranges:

Voltage: –10 volts to +10 volts Current: 4 to 20 milliamps

Resolution:

Default Scaling (16 bit) 312.5 microvolts per LSB step on voltage 0.5 microamps per LSB step on 4 to 20 mA No missing codes over 16 bits on voltage No missing codes over 14 bits on current NOTE: User scaling may introduce skipped codes in the lower 2 or 3 bits depending upon the factors used.

Accuracy: Calibration

Factory set at full scale = 10 volts ±2 millivolts on Base Converter module. Maximum errors at 25° C (77°F) are: Base Converter Voltage, ±.01% of full scale, ±.02% of value Base Converter Current, ±.05% of full scale, ±.1% of value Expander Voltage, ±.03% of full value, ±.02% of value Expander Current,

±.07% of full scale, ±.1% of value

Base Converter

Continually self-calibrates for zero and positive full scale (before user scaling) values. Field calibration not normally required; there is no zero adjustment. A trimpot on the Base Converter adjusts full scale value at 10V input. For critical applications this can be reset to compensate for ageing of the reference.

Accuracy: Linearity

±.02% of full scale over entire negative to positive range.

Temperature Coefficient

±5 PPM per °C typical ±15 PPM per °C maximum, voltage ±30 PPM per °C maximum, current

Input Impedance:

Voltage Inputs: Greater than 10 megohms at DC AC impedance, 20K ohms in series with 0.47 mfd capacitor. Current Inputs: 250 ohm, 0.1% precision shunt

Common Mode Rejection:

Voltage Range - Peak signal input must be between +13 and –13 volts with respect to the ANLGCOM terminal.

Sensitivity:

Response to common mode signals within the above limits is typically 70 dB CMRR, corresponding to a .02% full scale reading for a 0V input at 10 volts common mode. NOTE: Continuous input signals beyond the common mode range can result in abnormal conversions without causing alarms.

Crosstalk:

High-speed inputs on the Base Converter module may show some interaction between adjacent channels. This is typically .04% of the difference between the affected input and the adjacent channel input levels. The effect can be minimized by arranging inputs with similar levels on adjacent channels. There is no measurable interaction between Expander input channels.

Conversion Rate:

Base Converter inputs updated sequentially about every 2.4 ms to 2.8 ms (maxi- mum) for all 8 channels. One Expander input updated during each scan of the Base Converter inputs. Time between Expander updates = 44.8 x N ms

(N = number of Expander modules present).

Response Time:

Each input has a low pass filter with a 100 radians/second (0.01 second) cutoff. A digital filter on the Base Converter input channels adds a second pole at 450 radians/second. A sample and hold maintains full resolution. Settling times, to the specified accuracies, for a zero to full scale step input are as follows:

5.0% 30 milliseconds

1.0% 42 milliseconds

0.5% 51 milliseconds

0.1% 67 milliseconds

Input Protection:

Inputs isolated from VME backplane - but not between input channels. They are, however, protected from overvoltage to the levels listed below.

Impulse:

Inputs normally not affected by common mode damped ring wave of up to 1000 volts peak. Common or transverse mode peaks up to 2500 volts cause no damage, but may cause occasional bad data if they occur coincidentally with conversion of the affected channel.

Continuous Overvoltage:

Inputs survive common mode or normal mode 120 VAC or 125 VDC fault for at least 1 minute. Longer times may damage input current limiting resistor.

Damage limited to only the affected input.

Power Requirements:

Rack Backplane

+5 volts at 0.8A (4 watts) maximum for Base Converter

+5 volts at 0.4A (2 watts) for each Expander module

Field Side

No power required for the module; however, current for 4 to 20 mA inputs must be user supplied.