AC3 integration

AC3 analogue interface PC card - functionality overview

The AC3 is completely controllable by software. It contains a 16 byte register set in I/O space that can be accessed starting from the base address selected in section AC3 software interface.

The AC3 is a 16-bit IBM ISA bus plug-in PC card with two external connectors. It is simple to install and connects directly to a standard Renishaw multiwire probe signal cable.

AC3 is specifically designed for use with SP25M and is not compatible with Renishaw’s SP600 scanning probe (for SP600 use either AC1 or AC2).

The AC3 is very similar to AC2 but has additional features, which are specific to the SP25M probe. Full details are given in this section of the document.

SP25M and AC3 have been designed with a probe identification resistance of 9.375 kΩ.

NOTE: SP600 / AC1 or AC2 identification resistance is 30 kΩ.

AC3 also has its own board identification, which it presents to software.

The AC3 has the following attributes and functionality:

  • Performs probe management functions
  • Communicates status information to the host PC
  • Converts each of the SP25M analogue probe axis outputs into 2’s complement binary numbers accessible to the PC
  • 16-bit resolution capable of giving better than 0.1 μm resolution
  • Optically isolated PICS (Renishaw’s probe interconnection system) interface
  • Reading synchronisation using the PICS interface or software commands
  • Probe power removal using PICS
  • Full ISA bus address decoding
  • Optional 16-bit data transfers via the additional ISA 36-way connector
  • Interrupts generated on receipt of PICS or software AQUIRE command
  • ΔT controller compatibility is achieved by the use of option switches

The AC3 contains a number of registers that are accessible to software using I/O commands.