We CLAIM:
1. An isolator module for use in a surgical robotic system which comprises a robot arm
and a controller, the isolator module being configured to provide an interface between the
robot arm and the controller of the surgical robotic system, the isolator module comprising:
a first interfacing portion configured to: (i) transfer power from a first cable that is
connected to the controller, and (ii) transfer data to and from the first cable;
a second interfacing portion configured to: (i) transfer power to a second cable that is
10 connected to the robot arm, and (ii) transfer data to and from the second cable;
a third cable connecting the first interfacing portion to the second interfacing portion,
the third cable being configured to transfer data in both directions between the first
interfacing portion and the second interfacing portion whilst providing electrical isolation
between the first interfacing portion and the second interfacing portion; and
an isolated power converter configured to transfer power from the first interfacing
portion to the second interfacing portion whilst providing electrical isolation between the first
interfacing portion and the second interfacing portion.
2. The isolator module of claim 1, wherein the first interfacing portion comprises a first
control unit configured to:
transfer power received from the first cable to the isolated power converter; and
transfer data between the first cable and the third cable.
3. The isolator module of claim 1 or claim 2, wherein the second interfacing portion
comprises a second control unit configured to:
transfer power received from the isolated power converter to the second cable; and
transfer data between the third cable and the second cable.

4. The isolator module of any preceding claim, wherein data is transmitted through the
first and second cables according to a CoaXPress (CXP) data protocol.

5. The isolator module of any preceding claim, wherein the third cable is a fibre-optic
cable that is configured to transfer data between the first interfacing portion and the second
interfacing portion using light.

6. The isolator module of any preceding claim, wherein the data transferred from the
robot arm to the controller comprises a stream of sensor data.
7. The isolator module of claim 6, wherein the first interfacing portion further comprises
a signal conditioning module that is configured to receive a data stream from the third cable,
extract an embedded clock from that data stream and retransmit a fresh version of the data
stream to the first cable using a clean clock.
8. The isolator module of claim 6, wherein the second interfacing portion further
comprises a second signal conditioning module that is configured to receive a data stream
from the second cable, extract an embedded clock from that data stream and retransmit a
fresh version of the data stream to the third cable using a clean clock.
9. The isolator module of any preceding claim, wherein each of the first and second
interfacing portions comprises a small form-factor pluggable (SFP) interface module.

10. The isolator module of any preceding claim, wherein the module forms part of an
isolated ethernet switchboard.