VXI SM8000 user manual Command Register Write Only

VXI Technology, Inc.

	Command Register – Write Only
ADDR	Plug-In LA+0x106
		This nibble holds the number of bytes that are to be read back
		from the optical module. The value loaded into this nibble is
		dependent on the command that is required to execute in the lower
D15-D12	Read Byte Count	byte of this register. See the Optical Attenuator Operation section
		of the manual for the specific number of data bytes to be read back
		for each command. The count range is 0 to 7 bytes.
		The number of data bytes being read back, plus 1, must be loaded
		into this nibble.
		This nibble holds the number of bytes that are to be written to the
		optical module. The value loaded into this nibble is dependent on
		the command that is required to execute in the lower byte of this
		register. See the Optical Attenuator Operation section of the
		manual for the specific number of data bytes to be sent for each
D11-D8	Write Byte Count	command. The count range is 0 to 7 bytes.
		The Address, the Command Register, and the number of data
		bytes being sent must all be added together to calculate the
		number that is loaded into this nibble.
		I.e., The number of data bytes being sent, plus 2, must be loaded
		into this nibble.
		This Command Byte is sent to the optical module being controlled.
	Command Byte to	See the Optical Attenuator Operation section of the manual for
D7-D0		specific definitions of all the defined commands.
	Optical Module
		This command byte must be set prior to writing to the optical
		module’s data (attenuation level) register.

Note: See Command Register later in this section.

52 SM8000 Series Programming