User`s guide

MBX Driver Help
Cyberlogic Technologies Inc. - 12 -
controlling application, another application can immediately acquire this
control.
 Starting and stopping applications or changing the Peer Cop resources by
individual applications does not create any instability on the Modbus Plus
network.
 Any Peer Cop related operation by one application does not affect concurrent
Peer Cop operations from other applications. This is limited by the possibility
of conflicts when attempting to control specific outputs at the same node
address.
 Only Peer Cop features configured by the user through the Interface Adapter
Configuration Editor can be used by applications. This global configuration
ensures reliable operation on the Modbus Plus network and prevents
applications from unintentionally accessing and controlling Peer Cop data at
certain nodes.
 During the application exit (either normal or abnormal termination), the
specific outputs controlled by the application are either left in their last state
or restored to a pre-configured default state by the driver.
The MBX Driver also supports the Health Timeout Timer. The Health Timeout interval
specifies the minimum time period that the Peer Cop configured communication must fail
before the associated health bit is cleared. The recommended timeout value is 500 msec.
Caution!
There is a 20 msec latency in this timeout value. Thus, the maximum amount of time
that elapses before the health bit clears is the configuration time plus 20 msec.
For example, if the user configures the health timeout to be 60 msec, then the health
bit will be cleared no sooner than 60 msec and no later than 80 msec after
communication has been lost.
Software developers can refer to the MBX SDK (Software Development Kit for MBXAPI
and NETLIB compliant development) for a complete description of all API functions.
Interrupt/Polled Mode of Operation
The MBX Driver supports both interrupt and polled modes of operation. For Plug-and-Play
adapters, such as the PCI-85, the operating system assigns the system resources to the
card. In most cases the operating system selects interrupt mode.
Other interface adapter cards, such as the SA-85, can be configured for the interrupt
mode of operation. If multiple ISA adapter cards are used in the same system, each card
must use a different interrupt (IRQ) number. For these cards, the user must also ensure
that the configured interrupt number matches the jumper setting on the adapter card.
Otherwise, the driver will not receive any interrupts, resulting in a very low rate of
messages.
The interrupt mode of operation will typically provide higher message rates at the
expense of higher CPU load. However, for most applications, polled mode provides
adequate performance while significantly reducing system load.