Manual 07507026
Model 7026
Page 12
O
peration Manual
Chapter 7
Programming
The Model 7026 is a PXI register based card assembly designed for use with the National Instruments PXI
specification. You can program the Model 7026 in 8, 16 or 32 bit wide data format. By way of your PXI
controller, you can write the data to the appropriate register, shown on the register map, for the relay or
relays in the register that is being closed. When the data bit is true, the relay chosen is closed. You can
determine relay state in a register by simply reading the desired register. Data read back represents the value
of the desired register. In addition, you can read back the coil state to verify that the coil is driven correctly by
the program register. This scenario verifies that the program register has correctly controlled the relay coil.
A register map can be organized to show the relay designation at each register, followed by the register’s
functionality and the path connections to the front panel. PXI automatically assigns the starting address of the
card, called Bar0. Bar0 becomes the starting address of the first register. Each address location controls 8 bits.
The control functions using 16 format are shown in the illustration below.
Programming of the Model 7026 is very straight forward. The module is organized as a 1x32, two wire, 2 amp
general purpose relay board. The location of the first register is assigned by the PCI enumerator. This is
designated as "Bar0" or the starting address of the card. The program registers using 16 bit format are located
as follows:
Register #1 :
read/write function address
= Bar0 + 0000h
coil read back address
= Bar0 + 0008h
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RELAY
K16
K15
K14
K13
K12
K11
K10
K09
K08
K07
K06
K05
K04
K03
K02
K01
Register #2 :
read/write function address
= Bar0 + 0002h
coil read back address
= Bar0 + 000Ah
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RELAY
K32
K31
K30
K29
K28
K27
K26
K25
K24
K23
K22
K21
K20
K19
K18
K17
