Parameters that affect MS/TP communication - Metasys - LIT-12011034 - General System Information - Metasys System - Release 11.0

MS/TP Communications Bus Technical Bulletin

Brand
Metasys
Product name
Metasys System
Document type
Technical Bulletin
Document number
LIT-12011034
Version
Release 11.0
Revision date
2022-02-07
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 read the baud rate, see Reading the baud rate of devices.

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