Chapter 2 Configuration and Installation
© National Instruments Corporation 2-24 SCXI-1160 User Manual
4. Pull SLOT0SEL* low to deassert the SS* line and establish conditions for writing a new
slot-select number to the Slot 0 Slot-Select Register.
5. If you are not selecting another slot, write zero to the Slot 0 Slot-Select Register.
Figure 2-12 illustrates a read of the SCXI-1160 Module ID Register.
SS*
SERCLK
1
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
SERDATOUT
T
byte 0 = 12 byte 3 = 0
byte 2 = 0
byte 1 = 0
delay
0
0
0
0
SLOT0SEL*
DAQD*/A
Tdelay SS* high to SERDATOUT high 350 nsec
Figure 2-12. SCXI-1160 Module ID Register Timing Diagram
To read from the Status Register, follow these steps:
1. Initial conditions:
SS* asserted low.
SERDATIN = don't care.
DAQD*/A = 0.
SLOT0SEL* = 1.
SERCLK = 1 (and has not changed since DAQD*/A went low).
2. The Status Register of the SCXI-1160 consists of a single bit that the relays control. You do
not need to pulse the SERCLK to read the Status Register:
- Read the level of the SERDATOUT line. If it is low, the relays are switching. If it is
high, the relays are finished switching.
3. Pull DAQD*/A high. This disables further reads from the Status Register. If you wish, you
can write address FFFF (hexadecimal) to the Address Handler. This selects the Parking
Register and makes the module registers more immune to noise.
4. Pull SLOT0SEL* low to deassert the SS* line and establish conditions for writing a new
slot-select number to the Slot 0 Slot-Select Register.
5. If you are not selecting another slot, write zero to the Slot 0 Slot-Select Register.