User manual

104 Register-Based Programming Appendix B
ID and Device Type
Registers
ID Register: Reading this register returns: FFFF that shows that
Hewlett-Packard as the manufacturer and that the module is an A16

register-based device.
Device Type Register: Reading this register returns 0100
16
if the device is
the E1460A 64-Channel Multiplexer module.
Relay Control
Registers
Writes to the Relay Control Registers (base + 20
16
to 30
16
) which enables
you to switch the desired channel (banks 0-7) to COM or switch the desired
Channel Relay Control Register (channels 0990 - 0996). Any number of
relays per bank can be closed at a time.
Any bit pattern not indicated in the register maps result in the lowest-
numbered channel being closed. For example, to connect both upper and
lower banks to the analog bus, write a "1" to bits 2 and 3 of the (base + 30
16
)
to close bank 0990, relays 2 and 3. All other bits must be set to "0".
To reset the multiplexer (all relays open), you must write a "0" to each bit in
the Relay Control Registers. Reading the Relay Control Registers always
returns FFFF
16
. Register maps for Bank 0 through Bank 7 Relay Control
Registers and for the Channels 0990 - 0996 Relay Control Register follow.
r
base + 00
16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Write Undefined
Read Manufacturer ID - returns FFFF
16
in Hewlett-Packard A16 only register-based card
base +02
16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Write Undefined
Read 0100
16
Bank 0 Relay Control Register
base +20
16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Write* Undefined CH7 CH6 CH5 CH4 CH3 CH2 CH1 CH0
Read Always Returns FFFF16
* Write a "1" to close channel to COM
Bank 1 Relay Control Register
base +22
16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Write* Undefined CH7 CH6 CH5 CH4 CH3 CH2 CH1 CH0
Read Always Returns FFFF
16
* Write a "1" to close channel to COM