SBUS Driver Parameters

The SBUS driver supports the capability to apply different initialisation parameter values to specific I/O Devices. For further information, see Port-specific Parameters.

Note: Always seek the advice of Technical Support for this product regarding undocumented features.

[SBUS]Block

A value (bytes) used by the I/O Server to determine if two or more packets can be blocked into one data request before being sent to the I/O Device. For example, if you set the value to 10, and the I/O Server receives two simultaneous data requests - one for byte 3, and another for byte 8 - the two requests will be blocked into a single physical data request packet. This single request packet is then sent to the I/O Device, saving on bandwidth and processing.

Allowable Values 5 to 256

Default Value 8

[SBUS]Delay

The period (in milliseconds) to wait between receiving a response and sending the next command.

Allowable Values 0 to 300 (milliseconds)

Default Value 0

[SBUS]DisableGmtOffset

Forces the driver to use UTC time for reads and writes to the "K" time register.

Allowable Values 0 or 1 (disables the GmtOffset)

Default Value 0

[SBUS]FailOnBadData

Determine whether or not to force the display of good data within a block read which contains bad tags.

Allowable Values 0 or 1
0 = Ignore any bad tags in the block reads and just show 0 for those tags.
1 = Display reads that include a bad tag in the block with #BAD.

Default Value 1

[SBUS]GmtOffset

Specifies an offset from GMT in hours to use for reads and writes to the "K" time register.

Allowable Values

Local time zone difference on the computer:
-12 to +14 (hours)

Default Value 0

[SBUS]MaxPending

The maximum number of pending commands that the driver holds ready for immediate execution.

Allowable Values 1 to 32

Default Value 2

[SBUS]PollTime

The interrupt or polling service time (in milliseconds). Setting the polling time to 0 puts the driver in interrupt mode.

Allowable Values 0 to 300 (milliseconds)

Default Value 0

[SBUS]Retry

The number of times to retry a command after a timeout.

Allowable Values 0 to 8

Default Value 4

[SBUS]Timeout

Specifies how many milliseconds to wait for a response before displaying an error message.

Note: Only set this value if the time taken for the return of a data request is greater than the default of 1second. In this situation, set the value to a time period greater than the time taken for the return of a data request.

Allowable Values 0 to 32000 (milliseconds)

Default Value 1000

[SBUS]WatchTime

The frequency (in seconds) that the driver uses to check the communications link to the I/O Device.

Allowable Values 0 to 128 (seconds)

Default Value 30

[SBUS]SendBreak

This protocol can use three different transmission methods:

• Parity changing method

• Break mode transmission

• Data mode transmission.

Omission of a setting for this parameter will result in Parity changing method being implemented by default.

Allowable Values

0 = Parity changing method
1 = break mode
2 = data mode

Default Value 0

Note: This driver level parameter can be over-ridden on an individual port basis with the use of the SBUS.<PortName> parameter. See Port-specific Parameters.