Modbus - AKCP SPX+ Introduction Manual

SPX+ Introduction Manual - updated until firmware 4997

Modbus

MODBUS RTU is a non-proprietary serial communications protocol that is widely used in the process
control industry actuation. The sensorProbe+ can represent both "master" and "slave" devices and
supports both Modbus RTU (RS-485) and Modbus TCP protocols.
SP2+ Expansion and SPX+ currently only supports Modbus with RJ45 connector (RTU and TCP) on
its Expansion port. For just Modbus, only the pin 1 and 2 are used, being respectively, Modbus A/+
and Modbus B/-. You cannot use other sensor ports for Modbus other than the Expansion port.
Important: When you use Modbus, you can't connect expansion boards to the unit!
SP2+ Standard can only use the Modbus Virtual Sensors.
Note: Modbus queries are slow (up to 3 seconds). This is per Modbus protocol definition, it's not an
AKCP limitation. The more sensors you have, the bigger the polling interval must be.
Configuring the Modbus options and more information about this feature is explained in the separate
SP+ Modbus manual.
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