VXI Microwave Matrix, SM7100 user manual Bbm/Mbb

VXI Technology, Inc.

Control Register - Read and Write (continued)

		0	= BBM (Break-Before-Make) / MBB (Make-Before-Break) is disabled
		1	= BBM/MBB operation is enabled
		Pon state = 0
		NOTE: This bit should remain a 0 (disabled) for the SM7100.
		If this bit is set, the relays will be sequenced to effect proper BBM or MBB
		operation. If this bit is not set, the module will process the newly written relay data
		as immediate data, writing it directly to the relay driver ports. No BBM or MBB
		sequencing will take place.
		While this feature is enabled, the initial write to the module will start the delay
D7	BBM/MBB	timer running		and begin the BBM or	MBB operation. Since the relays are
		controlled by		the 16-bit registers, only	the effected 16 relays will perform the
	Enable Bit
		BBM/MBB operation. To overcome this fact, any subsequent writes to the module,
		during the initial delay timer time-out period, will be accepted and processed. In
		addition, the delay time will be reset and begin counting down again. Once the
		delay timer has timed-out (this indicates that the relays have settled into their
		BBM/MBB state), writes to the module will not be accepted and may result in a
		Bus Error depending on the value programmed into the delay timer. This is because
		the delay timer is reset at the end of the initial time-out and is used to time the final
		relay closure into their post BBM/MBB state. The module Busy signal will only
		complete once the final relay closure state is reached.
		If this bit is set and no value has been loaded into the Delay Register, the module
		will act as if this enable bit is not set and load all of the relay drivers with
		immediate data.
		0	= BBM operation is selected
D6	BBM/MBB	1	= MBB operation is selected
		Pon state = 0
	Select Bit
		NOTE: This bit should remain a 0 (BBM) for the SM7100.
	Access	0	= non-active
		1	= active
D5	LED Fail	Pon state = 0
	Bit	Lights the Access LED red when activated.
	Relay	0	= The Openbus and Front Panel Open signals are not enabled to reset the relays
D4	Reset	1	= The Openbus or Front Panel Open signal may be selected to reset the relays
	Enable Bit	Pon state = 0
	Relay	0	= Front Panel Open signal is selected to reset the relays
		1	= The Openbus signal is selected to reset the relays
D3	Reset	Pon state = 0
	Select Bit	Many plug-in modules may be programmed to be listeners on the Openbus.
	Openbus	0	= Disables the Front Panel Open signal from driving the Openbus signal
D2	Out Enable	1	= Enables the Front Panel Open signal to drive the Openbus
	Bit	Pon state = 0.

30 SM7100 Programming