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Scale interface (15W HDD socket)

UCC AI provides a digital interface for Renishaw digital incremental and absolute encoders (BiSS protocol only), as well as dual signal interface for dual TONiC or Signum systems.

UCC AI can also be used with compatible 3rd party incremental encoders.

Connector details

The port uses a 15-way high-density D-socket, the connections are shown in the table below.

NOTE: If the machine scale is of a different format (e.g. analogue, single-ended) then this will require an external adaptor.

UCC BI scale inputs
Pin no.

Function

Function

Incremental

Absolute

1

Reserved

Reserved

2

0 V scale supply

0 V scale supply

3

Error -

Reserved

4

Reference mark -

Reserved

5

B signal -

MA -

6

A signal -

SLO -

7

+V scale supply

+V scale supply

8

+V scale supply sense

+V scale supply sense

9

0 V scale supply sense

0 V scale supply sense

10

/Limit switch Q/ (active low)

Reserved

11

Error + or /limit switch P/ (active low)

Reserved

12

Reference mark +

Reserved

13

B signal +

MA +

14

A signal +

SLO +

15

0 V scale supply (inner screen)

0 V scale supply (inner screen)

Shell

Screen

Screen

+V scale can be adjusted independently for each scale interface port.

If the scale power sense wires are connected to the respective scale power supply signals at the readhead, the voltage will automatically adjust to maintain +5 V at the readhead.

If the sense wires are open circuit then the voltage can be adjusted through the UCCsuite software. In both cases the scale supply voltage is nominally +5 V and can be adjusted to a maximum of +7 V. The sense and supply signals should be connected as close to the encoder as possible (see diagram below):

Scale port and encoder connection - UCC AI

The scale inputs support a quadrature waveform with a minimum edge separation of 50 ns, which equates to 20 million counts per second with an ideal waveform.

Encoder resolutionMaximum move speed
1 µm20 m/s
0.1 µm2 m/s
50 nm1 m/s
1 nm0.02 m/s

UCC AI scale signal interface circuit

Scale inputs - UCC AI

UCC AI scale error interface circuit

Error interface circuit - UCC AI

The UCC AI supports the error signal provided by Renishaw's digital incremental encoders. The UCC AI can also detect tri-state conditions on the A and B signals. If the error signal is not integrated into the connected encoder,then the user should connect pin 3 (Error - ) to pin 7 (+V scale).

UCC AI scale limit switch interface circuit

If scale limit switch signals are integrated into the the encoder being used then the following diagram should be referenced to ensure compatibility with the UCC AI.

Limit switch interface circuit - UCC AI