KNX Parameters

CacheLifeTime

The time a cache value will remain active for. Once an item reaches half its cache life time, the driver will process a read request for the group address to refresh the cache value.

Any positive integer representing number of seconds.

300 (seconds)

IgnoreRouterDisconnect

When the value of this parameter is set to 1, the driver will not take the I/O device offline if a disconnect request is received from the router.

0 or 1

0

InitTimeout

The maximum time the I/O server is allowed to wait for replies to be received from all group addresses to populate the cache before either aborting the InitUnit or bringing the unit online.

Any positive integer representing number of seconds.

120 (seconds)

InterFrameDelay

The minimum timing delay between successive transmitted frames by the driver. This can be used to avoid flooding the buffers of gateway device.

See Maximum Transmission Rate Control.

Any positive integer representing number of milliseconds.

50 (ms)

LocalIPAddress

Sets the local IP address the I/O server will attempt to bind to.

Any four octet dotted notation IP address. e.g. 192.168.1.1

0.0.0.0 (Instructs the IP stack to bind to any/ all available network interfaces)

LocalPort

Sets the local port number the I/O server will attempt to bind to. For the KNXnetRouter, 3671 is the standard KNXnet/IP Port). If LocalPort is not configured it will default to the MulticastPort only for multicast mode of communication.

Any valid port number

3671

MaxTransmitRate

The maximum traffic rate that the driver is allowed to generate in bits per second. The KNX wire protocol is a 9600 bps serial protocol. This parameter allows the maximum traffic rate generated by the KNX driver to be controlled.

This only governs outbound traffic. As such it should be set to a lower value than might be expected, as read requests will require bandwidth for a reply.

In a large network with many IP router devices with concise filter tables, it may be helpful to set this value much higher then 9600, provided the engineer has tested and confirmed that the packet buffers of any individual IP router will not be overflowed.

See Maximum Transmission Rate Control.

Any positive integer representing a number of bits per second. (A value less than 200 is not recommended.)

2000 bps

(approx. 20% of maximum bus throughput)

MulticastAddress

Sets the multicast IP address the I/O server will attempt to communicate with.

Any four octet dotted notation IP address within the range of 224.0.0.0 to 239.255.255.255
e.g. 224.168.1.1

224.0.23.12 (Standard KNXnet/IP multicast address)

MulticastPort

Sets the multicast port number the I/O server will attempt to send packets to. For the KNXnetRouter, 3671 is the standard KNXnet/IP Port.

Any valid port number

3671

OfflinePollTime

The polling period (in seconds) of tags which have bad quality.

Any positive integer representing number of seconds.

CacheLifeTime/2

PhysicalAddress

Sets the physical address for the Plant SCADA I/O server in the KNX network. All messages sent from the Plant SCADA I/O server will be sent with this address as the source address.

If the value is larger than 65535, it will be masked to only use the lower 16 bits. The value represents Area Number (bits 12-15), Line Number (bits 8-11), Device Number (bits 0-7).

The value has to be specified in decimal. If hexadecimal notation is used the address will resolve to 0.

Any 16 bit value

0

Retry

Determines the number of retries the driver should try to send the read request when there is no response from router. After exceeding the number of retries, the driver will set the quality of the tags in the read request to 'Bad' and stop sending read requests for these tags until reaching half of its cache life time.

Note: Changing the default value of this parameter is only useful to decrease the network traffic between the driver and KNX router caused by unsuccessful read requests.

Any positive integer representing the number of retries.

Zero (0). The driver will not set the tag quality to 'Bad' and will continue sending read requests after exceeding the number of retries.

Timeout

Specifies the time delay between each read request.

0 to 32000 (milliseconds)

5000 milliseconds (5 seconds

TTL

Sets the maximum time-to-live (TTL) on outbound multicast IP packets.

This should only be adjusted on the advice of network administrator. It would only be necessary to control the routing of multicast packets from one IP subnet to another.

Any positive integer

16

UnitType

Determines the type of bus interface unit the device should communicate with.
'KNXnetRouter' represents an KNXnet/IP device configured for routing.

KNXnetRouter

KNXnetRouter

TunnelConnectionRetries 1

Determines the number of retries the driver should try to connect with the router when the initial connection request is unsuccessful.

For example, If the value is 1 then it will retry to send the connect request one more time after the initial connect request is unsuccessful.

Once the number of retries ends, the driver will not make further attempts to connect and will report the unit offline.

0 - 5

3

TunnelConnectionTimeout 1

Connection related packets are time bound. If no response received from router within this timeout period, then the driver will ignore any later responses. The timeout option helps driver to determine either to send the packets again or to make the unit offline.

Any positive integer representing number of milliseconds.

10000 (ms)

TunnelConnectionActive

Defines the interval to periodically check the connection state with the router. Driver sends a CONNECTSTATE_REQUEST to the router to verify that the connection is active. These parameters can also be configured at unit level. The unit has to be configured for unicast communication.

5 - 100 seconds

60 (seconds)