Isolation and common pins on RMC modules

Forum: Motion Control Motion System Design
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This topic explains the isolation of the RMC modules. This information is important for properly wiring the common pins and avoiding ground loops. The isolation is functional isolation and not for safety. Isolation is not tested on individual modules during production.

RMC75

  • The power input is isolated.
  • The Ethernet port on the RMC75E is isolated.
  • The USB on the RMC75E is not isolated.
  • The serial communication on the RMC75S is isolated. The serial Monitor port is not isolated.
  • The PROFIBUS communication on the RMC75P is isolated. The serial Monitor port is not isolated.
  • The analog outputs and the analog, MDT/SSI, and quadrature inputs on the axis modules are not isolated from the RMC75 base module.
  • The discrete I/O on the axis modules are isolated.
  • All Common pins on an axis module are internally connected.
  • The expansion modules are isolated. The inputs and/or outputs on each expansion module are isolated as a group.

RMC150

  • The power input is isolated.
  • The Ethernet port on the RMC150E is isolated.
  • The USB is not isolated.
  • The analog outputs are isolated per module, and the analog inputs are isolated per module, and isolated from the analog outputs.
  • The MDT, SSI, Quadrature, and Resolver transducer inputs are not isolated.
  • All discrete I/O are isolated.
  • UI/O: Analog inputs 0-1 are isolated as a single group. The High-speed inputs are isolated as a group. Discrete I/O are isolated as a group.

RMC200
In general, all inputs and outputs are isolated except the USB port.

  • All I/O on each module is isolated from the I/O on other modules.
  • PS4D/6D: The power input is isolated.
  • CPU40/20L: The Ethernet ports are isolated, and the discrete I/O are individually isolated. The USB is not isolated from the module’s internal common. The CPU20L power input is isolated.
  • A8: Inputs 0-7 are isolated as a group and share the same common.
  • S8: Inputs 0-7 are isolated as a group and share the same common.
  • Q4: Quadrature inputs 0-3 are isolated as a group and share the same common. Discrete I/O are individually isolated.
  • CA4: Analog outputs 0-3 are isolated as a group and share the same common. Discrete I/O are individually isolated.
  • CV8: Analog outputs 0-7 are isolated as a group and share the same common. Discrete I/O are individually isolated.
  • D24: I/O points 0-19 are divided into three separate isolation groups. Inputs 20-23 are individually isolated.
  • U14: Analog inputs 0-3 are isolated as a single group. Analog outputs 0-1 are isolated as a single group. The High-speed inputs are isolated as a group. Discrete I/O are individually isolated.