Channel Mode (S1 Switch); A/D Converter Range (S2 Switch); Trigger Edge (P8 Jumper) - Measurement Computing PCIe-DAS1602/16 User Manual

PCIe-DAS1602/16 User's Guide
Before installing the PCIe-DAS1602/16 in the computer, make sure that the board is configured with the
settings that you want. Review the following information to change the default configuration of a jumper or
switch on the PCIe-DAS1602/16 board.
Board switches are covered by analog input shield
To access the channel mode switch (S1) and the A/D range select switch (S2), remove the metal analog input
shield that covers them. This shield is secured to the board with two screws.

Channel mode (S1 switch)

Use the S1 switch to set the channel mode configuration. Configure the PCIe-DAS1602/16 analog inputs for
either 8 DIFF channels or 16 SE channels.
Use SE input mode if you have more than eight analog inputs to sample.

Use DIFF input mode to allow for up to 10 V of common mode rejection. This mode provides better

noise immunity.
The S1 switch is factory-configured for 8 DIFF inputs, as shown in Figure 3. To configure for 16 SE channels,
set this switch to 16.

A/D converter range (S2 switch)

Use the S2switch to set the A/D converter range. This switch controls all A/D channels.
Switch S2 is factory-configured for bipolar. To configure for unipolar, set this switch to UNI.

Trigger edge (P8 jumper)

Use the P8 jumper to set the A/D pacer clock trigger edge. This jumper selects the edge that initiates the A/D
conversion when using the internal pacer clock.
Jumper P8 is factory-configured for rising edge.
When using the falling edge to start the conversion, the A/D may be falsely triggered by glitches in the 8254
pacer clock initialization. If the PCIe-DAS1602/16 is replacing an older series MCC board, using the rising
edge to start the conversion may lead to timing differences.
For compatibility with MCC software and third-party packages, leave jumper P8 in the default rising edge
position.
Figure 5 and Figure 6 show the edge selection options for jumper P8.
Figure 5. Jumper P8 set for rising edge
Figure 3. 16/8 channel select switch (S1) default setting (8)
Figure 4. A/D range select switch (S2)
Figure 6. Jumper P8 set for falling edge
8
Installing the PCIe-DAS1602/16