National Instruments 7334 - Manual (Page 37)

Chapter 5 Signal Connections
7344/7334 Hardware User Manual 5-12 ni.com
Analog Inputs
The 7344/7334 controller has the following ADC input signals:
• Analog Input <1..4>—The 7344/7334 controller includes an eight
channel multiplexed, 12-bit ADC capable of measuring ±10 V, ±5 V,
0–10 V, and 0–5 V inputs. ADC channels 1 through 4 are brought out
externally on the 68-pin motion I/O connector. ADC channels 5
through 8 are connected internally as shown in Table 5-2. These
signals can be used for ADC test and calibration.
You can configure each ADC channel for motion feedback, simple
A/D conversion, or both.
You can read the digital value of analog voltage on any of the eight
ADC channels of the controller by using the Read ADC function. The
range of values read back and the voltage resolution for each setting are
shown in Table 5-3. The voltage resolution is given in volts per least
significant bit (V/LSB).
When configured as analog feedback, an analog sensor acts like a
limited range absolute position device with a full-scale position range
as indicated in Table 5-3. You can map any ADC channel as feedback
to any axis.
You can enable and disable individual ADC channels in software.
You should disable unused ADC channels for the highest multiplexer
Table 5-2. Internal ADC Channels
ADC Input Signal
5 Filtered +5 V
6 Floating (NC)
7 Analog Reference (7.5 V)
8 Analog Input Ground
Table 5-3. Analog Input Voltage Ranges
Input Range Binary Values Resolution
±10 V –2,048 to 2,047 0.0049 V/LSB
±5 V –2,048 to 2,047 0.0024 V/LSB
0–10 V 0 to 4,095 0.0024 V/LSB
0–5 V 0 to 4,095 0.0012 V/LSB