User`s manual

134 Register-Based Programming
There are eight relay registers driving the 256 channels of the Multiplexer
and two tree relay registers controlling the 21 tree relays. The second tree
relay control register also controls nine C relays used for signal routing. The
analog bus register controls five analog bus connection relays. All these
relay control registers are readable/writable (R/W) registers. Writing a “1”
to one bit will close the respective relay and writing a “0” will open the relay.
When power-on or reset the Multiplexer, all the control relays are open and
when you read from these registers, all the bits are zero.
ID Register Reading the ID register returns FFFF
h
indicating the manufacturer is Agilent
Technologies and the module is an A16 register-based device.
The “Programming Example” on page 141 shows how to read the ID
Register.
Device Type
Register
Reading the Device Type Register returns 026B
h
(decimal = 619) which
identifies the device as the Agilent E8462A 256-Channel Relay
Multiplexer.
The “Programming Example” on page 141 shows how to read the Device
Type Register.
Status/Control
Register
Writing to the Status/Control Register (base + 04
h
) enables you to
disable/enable the interrupt generated when channels are closed or opened.
The “Programming Example” on page 141 shows how to read the Status
Register.
base + 00
h
1514131211109876543210
Write Undefined Logical Address
Read Manufacturer ID - returns FFFF
h
in Agilent Technologies A16 only register-based card
base + 02
h
1514131211109876543210
Write Undefined
Read 026B
h
, 619
10
base + 04
h
1514131211109876543210
Write
undefined
Set Interrupt Level D undefined SYS-
FAIL
R
Read 0 M undefined Interrupt Level B D undefined 1 1 SYS-
FAIL
R