National Instruments Deterministic Ethernet Expansion Chassis NI 9144 - Manual (Page 53)

© National Instruments Corporation 53 NI 9144 User Guide and Specifications
Where:
6:2 Clock Divisor
1:0 Clock Source
IEPE Enable <3:0>
When set, the corresponding channel’s relays are switched to IEPE operation. IEPE operations
switches the AC/DC relay to AC mode and enables the IEPE relay to send the current to the IEPE
sensor.
AC/~DC <3:0>
Controls the AC/DC relay when IEPE is not selected. If IEPE is enabled, then these bits have no
meaning as AC mode is always selected with an IEPE operation.
Clock Divisor
The NI 9234 divides the clock source (internal or external) by this value and uses it as the
converters’ oversample clock. The data rate is equal to 1/256 times this oversample clock frequency.
Valid values for Clock Divisor are from 1 to 31, and the final divided clock must be between
100 KHz and 12.8 MHz.
Clock Source
0b00 = 0 The OCLK pin is used as the oversample clock source.
0b01 = 1 The 12.8 MHz internal clock is used as the clock source and this 12.8 MHz
is driven onto the
OCLK pin.
0b10 = 2 The internal clock is used but not driven onto OCLK pin. Currently, this is
the required clock setting.
0b11 = 3 Reserved.
Table 47. NI 9234 Scan List Format (Continued)
Bits Field