VXI SM8000 - Manual (Page 55)

VXI Technology, Inc.
SM8000 Series Programming 55
W RITING TO THE R ELAY R EGISTERS
If the SM8000 is used to drive single-mode prism switches, in either latching or non-latching
configurations, setting the switches is accomplished through writing to the Relay Register located
at Relay Register Offset H0000. Each bit, of this 16-bit register, represents the state of the relay
(1 = closed, 0 = open). (Note that bits 15 through 12 are unused.) To change the state of any
relay, it is only necessary to write a 16-bit integer to the specified register with the new
configuration. For example:
• writing a data value of "0" to the register at offset "0" would open the 12 available switches
• writing a data value of 4095 (0x0FFF) to the same register would close the 12 switches
• writing a data value of 4094 (0x0FFE) to the same register would close all switches except
switch number 1
Relay Register 00 – Read and Write
ADDR Plug-In LA+0x000
D15-D12 Unused Write has no effect. Read back as 1111.
D11-D0
1x2 or 2x2 Optical
Prism Switch
Control Register
0 = Opens optical path.
1 = Closes optical path.
Pon state = 0
A read of this bit location will indicate whether the optical path is
either closed or open. This register controls the possible 12 prism
switches that may be driven by the SM8000.