With the Bachmann M1 Modbus master read/write access to the data from any external standard-conformant Modbus slave device is possible. The holding register, register, coils und discrete inputs of the external slave-devices are mapped to logical hardware modules of the control system per hardware modules. The cyclic update is executed automatically, the values remain available in the process image. Queries to the slaves are summarized automatically in this process to reduce the load. 

In addition, the Modbus master offers a function interface via which any Modbus requests can be sent to the slaves. The standardised error messages (Modbus exceptions) are passed through to the application software, the connection status is identified via diagnostics variables. 

All Ethernet ports for Modbus TCP and UDP, as well as all serial interfaces for Modbus ASCII and RTU, are available. These can also be distributed spatially to substations of the control system. 



  • Supported protocols:
    • Modbus TCP
    • Modbus UDP
    • Modbus ASCII
    • Modbus RTU
  • Use of the onboard interfaces of the CPUs
  • Possibility of spatial distribution of the interfaces via FAST substations with EM213 or RS204 modules
  • Mapping of the contents of the »Modbus Primary Tables« to virtual channel values
  • Multiple networks parallel 
    (also for different modes)
  • Gateway functionality 
    (also to other bus systems)
  • Investment protection thanks to extremely wide distribution
  • Compatibility and openness
  • Easy handling


Modbus Master

Modbus Master EN
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Modbus Master EN
Modbus Master DE
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Modbus Master DE

System overview