Parameters That Affect MS/TP Communication - BCPro - LIT-12011908 - General System Information - BCPro System - 4.0

MS/TP Communications Bus for the BCPro System Technical Bulletin

Brand
BCPro
Product name
BCPro System
Document type
Technical Bulletin
Document number
LIT-12011908
Version
4.0
Revision date
2020-03-16
Language
English

The following parameters can be adjusted to tune MS/TP communication.

Important: Do not adjust attributes with which you are unfamiliar. If set improperly, the following parameters can adversely affect MS/TP communication.

The Baud Rate Selection attribute specifies the baud rate. If the baud rate is forced to be different from other devices on the bus, communication ceases. To change the baud rate, see Changing the Baud Rate of an Entire Bus.

The Max Master attribute specifies the highest address that can be a master on the bus. By adjusting this value, you can prevent some devices from coming online as bus masters. All devices on the bus must have the same Max Master attribute value to prevent the token from going to a device with an address above the Max Master attribute value.

The Max Application Protocol Data Unit (APDU) Length Accepted attribute specifies the largest data packet that is allowed on the bus. If set improperly, this parameter can cripple the bus.

The APDU Timeout attribute determines how long the BACnet Router waits for an acknowledgement from a device when the message can be sent in one transmission. If set too low, many messages fail. If set too high, error recovery is delayed. You can change this value in special situations when dealing with third-party devices or overloaded networks.

The APDU Segment Timeout attribute determines how long the BACnet Router waits for an acknowledgement from a device when the message is sent in multiple segments. If set too low, many segmented messages fail. If set too high, error recovery is delayed. You can change this value in special situations when dealing with third-party devices or overloaded networks.

The APDU Retries attribute determines how many retries are allowed when trying to recover from an error. If changed improperly, the network may slow down or become more sensitive to noise. You can change this value in special situations when dealing with third-party devices or overloaded networks.