Linak TECHLINE LA35, Руководство по установке

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The RS485 standard basically specifies a system consisting of 32 slaves without the use of repeaters. Modern
transceivers allow for even more, as their bus load is less than the maximum allowed by the RS485 standard. The
LINAK MODBUS actuators use such modern transceivers, theoretically supporting up to 256 nodes. In real life this
number is reduced by the below listed operating conditions:
• The baud rate
• The total length of the trunk cable
• The total length of the derivation cables
• The quality of the cabling
• The functionality i.e. the poll rate
Based on our tests, a bus string with a master, 32 LINAK actuators and no 3’rd party slaves will work under the
following conditions:
• Baud rate: Up to 19200
• Data cable: Following the guidelines in the following section DATA cable
• Derivation cables: Standard LINAK cable supplied with MODBUS actuator, not extended
• Termination: In both ends of string
• Total string length: 1000 m
If your MODBUS system either:
• includes more than 32 actuators
• the trunk cable exceeds 1000 m
• the derivation cables are extended
• includes 3
rd
party slaves
..then you have to test if the installation needs repeaters or other actions to provide a stable communication level.
Wiring in general
Be careful not to run any AC cabling in parallel with the wiring for the actuator system as this will create
a noisier environment.
Power up rules
• It is preferable not to have power on the power line when you connect or disconnect
the actuators.
• Fuse selection: It is recommended to install a fuse for each actuator in a string (prevents
a dead string (series of actuators) in case of an error (e.g. short circuit)). Alternatively, a fuse for
each power supply must be installed. It is also recommended to use a current limited power supply.