Attributes to Configure in the Scan Device Point

Attribute Name Description

remote ID A user supplied RTU address (unit) number.

comm info

This table specifies the following information:

Field Number	Field Name	DE Type	Possible Values
0	key up delay	rtINT16	-32,767 to 32,767 (msec)
1	key down delay	rtINT16	0 to 32,767 (msec)
2	channel clear delay	rtUINT16	0 to 65,535 (msec)
3	turnaround delay	rtUINT16	0 to 65,535 (msec)

Where:

Field Name	Description
key up delay	The desired time to wait (in milliseconds) after asserting RTS (request to send), before sending data. If the value is 0 (zero), no RTS is asserted. If the value is greater than zero, the host will wait that number of milliseconds, after asserting RTS, before beginning transmission, regardless of the value of CTS (clear to send). If the value is less than zero, the host will wait until either the CTS signal is received, or the specified number of milliseconds has expired before transmitting. If the specified time expires before CTS is received, the transmission fails.
key down delay	The desired time to wait (in milliseconds) after the last data character has been sent, before resetting RTS (request to send). This should be a positive number; if the value is negative, the minimum time of rtNap() is used (see Section 3 of the `RTAP Reference Manual` for details).
channel clear delay	The desired time to wait (in milliseconds) for the DCD (data carrier detect) line to clear before asserting RTS. If this value is zero, the DCD line will be ignored. If the value is positive, the host will wait the specified number of milliseconds for the DCD to clear before asserting RTS. If the DCD line has not cleared before the specified time has expired, the transmission fails.
turnaround delay	The desired time to wait (in milliseconds) after data has been transmitted in either direction, before a transmission in the opposite direction is initiated. This time must be at least the sum of the "channel clear delay", "key up delay" and "key down delay".

If this table is not specified, then the "comm info" values specified in the communication point will be used.

comm optimization

This attribute specifies whether the scan task should attempt to optimize data transfers by merging multiple scan input records into a single request object. This may involve altering the qualifier, range start and range length field values specified in the scan input table (see also Data Transfer Optimization).

The contents of the scan input table is not changed, only the values used internally and in the object request.

message timeout

This attribute specifies the time period that an application message should be received from the remote device. The remote device may respond quickly to the data link frame, but may take longer to complete the request, hence the different timeout value.

This value is different than the reply timeout attribute in the communication port point as the latter specifies the timeout period for a data link layer.

Because the application layer uses the data link layer to send the message, the minimum timeout period is the communication port point's "reply timeout" times the communication port point's "retry count" on failure and just the "reply timeout" value on success.

message retries

This attribute specifies the number of times that an application message will be re-tried if no response is received from the remote device within the "message timeout" period.

This value is different than the retry count attribute in the communication port point as the latter specifies the retry count at the data link layer.

datalink confirm Specifies whether we should send messages out with or without datalink confirm set.

phone number This specifies the phone number to dial when the scan task is talking to a modem.

enable class assign This specifies whether the scan task will issue a class assign message for the objects specified in the class number field in the scan input table.

enable class unsol

This specifies whether the scan task will use the DNP class number when sending the enable/disable unsolicited message. The class number is as specified in the class number field in the scan input table.

If scan input records are disabled, and this attribute is enabled, a DNP disable unsolicited message will be sent using the class number configured for these records. This may not be the desired effect if only some of the scan input records for a particular class is disabled.

poll sets timestamp

Specifies whether polls will save the current poll time into the scan task buffer (if enough space has been allocated, see st buffer size). This is useful if static/event objects are received via SRBX and integrity polls have been configured. In this case if the polled return value(s) indicates a change, the current time will be saved into the scan task buffer as the objects timestamp value. Note that if the object has a "flag" value allocated in the scan task buffer and the polled object does not have a flag value, the flag value in the scan task buffer will not be changed. The following objects are affected by this flag:

Object 1, Variation 1 (Single Bit Binary Input)
Object 1, Variation 2 (Binary Input with Status)
Object 20, Variation 1 (32-bit Binary Counter)
Object 20, Variation 2 (16-bit Binary Counter)
Object 20, Variation 3 (32-bit Delta Counter)
Object 20, Variation 4 (16-bit Delta Counter)
Object 20, Variation 5 (32-bit Binary Counter without Flag)
Object 20, Variation 6 (16-bit Binary Counter without Flag)
Object 20, Variation 7 (32-bit Delta Counter without Flag)
Object 20, Variation 8 (16-bit Delta Counter without Flag)
Object 30, Variation 1 (32-bit Analog Input)
Object 30, Variation 2 (16-bit Analog Input)
Object 30, Variation 3 (32-bit Analog Input without Flag)
Object 30, Variation 4 (16-bit Analog Input without Flag)
Object 30, Variation 5 (Short Floating Point Analog Input)
Object 30, Variation 6 (Long Floating Point Analog Input)

debug level A debug level used to determine the amount of information printed to the debug device. Higher debug levels print more detailed information. A debug level of zero indicates that no debug information is to be printed to the debug device.

clear stats Indicates whether the device stats vector will be zero'ed the next time it is read from the database.