User`s manual

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EX7000-OEM Web Page Operation 39
Continuous Mode
Connecting non-latching devices to any bank of the Relay Driver Board will dictate that bank
must be operating in continuous mode. Commanded by software, the latch signal driving the FET
will change state to activate/deactivate FETs and continuously stay in that state until the next
command. All Relay Control Drive bits within a bank will change state at the same time.
Continuous mode requires a power supply capable of sustaining the high current requirement. The
user must allow an appropriate amount of time after the Relay Control Drive bit changes state for
the relay to settle. This is typically between 10 ms to 30 ms.
F
IGURE 5-3: CONTINUOUS OPERATION MODE
Pulse Mode
Connecting latching devices to any bank of the Relay Driver Board will dictate that bank must be
operating in pulse mode. Commanded by software, the latch signal driving the FET will change
state to activate FETs and then change state back when the settling time is reached. All Relay
Control Drive bits within a bank will change state at the same time. Certain latching devices will
require a reset signal to move all latches to a known state prior to a new state is applied. The Reset
signal will be a pulse with the same duration as the Relay Control Drive. The pulse width should
exceed the settling time specification for the relays being used. This value will be used as both
pulse width and settling time.
F
IGURE 5-4: PULSE OPERATION MODE
NOTE There is no current monitoring capability on the EX7000. It is the user’s responsibility to estimate
the total current requirement and provide sufficient power supply current.
The user can mix and match non-latching and latching devices among the banks. For instance,
bank 1 and 3 can be all latching, bank 2 can be non-latching. The Relay Driver Board, if set up
properly, will be able to control all of the devices.
In case of multiple Relay Driver Boards, all devices in different boards can be controlled in
parallel as long as the current requirement is met. The user does not have to wait for one Relay
Driver Board to finish its operation before moving to the next. On the contrary, the user can also
control one Relay Driver Board at time. The settling time in case of multiple Relay Driver Board
will be the longest between the boards, multiply with the aggregate number of banks connecting to
latching devices.