General Parameters

[IEC870IP] Parameter

Description

Allowable Values

Default Value

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.

Note: This is a common I/O server parameter that does not impact this driver as blocking is not supported. There is no benefit to changing the value of this parameter.

512

512

Delay

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

Note: Do not change this parameter from the default value of 0 (zero), as applying a delay will impact the performance of this driver.

0
(milliseconds)

0

MaxPending

This parameter limits the number of outstanding asynchronous request issued from the I/O server to the driver.

1 - 32

1

Polltime

This parameter is required to the clear the receive queue.

Each poll time, the driver will check for any entries in the send and receive queue. If any entries are found, the driver will process the data from the queues into the driver's data image. From there, the driver will push into the DRI and SCADA system.

The size of the receive queue is governed by the parameter [IEC870IP]ReceiveQueueSize (default = 1000)

0 - 300
(milliseconds)

100

Retry

If a DCB command to the driver times out, this parameter determines how many times the command will be tried again before reporting the driver offline.

0 - 8

1

Timeout

This timeout relates to any DCB request issued to the driver.

If a response is not received, this parameter determines how long to wait before the request is issued again.

The driver will be considered offline if no response is received following the number of request attempts specified by the Retry parameter.

0 - 32000
(milliseconds)

2000

Watchtime

The frequency with which the I/O server checks the communications link to an I/O device if the device is determined to be offline.

0 - 128
(seconds)

1