Renishaw RCU10, Installation And User Manual, Page: 30 / 202

System design 2-7
WARNING: To ensure that the motion control system receives quadrature of the
expected resolution and frequency, it is important to set both the input and output
resolutions of the Renishaw system correctly. If the quadrature resolution is set
incorrectly, the axis may move for distances and at speeds that are not expected. For
example, if the output resolution of the RCU10 system is set to double that of the
controller input, the axis may move twice as far and twice as fast as expected.
J4 – Reference switch port
The reference mark input may be used to receive a reference position marker pulse. Two
options are available when configuring the RCU10: either a reference mark derived from
the encoder (through the encoder where Z and /Z are the reference mark input lines), or
connected to the REF input. The REF input can accept a range of actuator types that
have solid state (high side or low side), 5 V logic signal or mechanical switch output
formats.
The reference process is triggered by the current’s rising edge on switch closure. The
reference signal must last for at least one input encoder pulse transition and, once the
process has been started, another cannot be activated for a period of 1 second. Providing
this is adhered to, no restriction is placed on axis velocity during referencing, except for
the repeatability caused by the time delay introduced by the interface circuit. Please refer
to Appendix B for connector pinout and hardware installation details and section 2.5 for
signal and phasing information.
Figure 2.6 – Reference mark actuator connection
Notes: TTL driver signals are not suitable for use here. The thresholds are 3 V high
and 1 V low.
The reference mark signal will only function in conjunction with quadrature, ie
not stationary.
RCU10
100 m A MA X
+
5 V
4
3
5 V
driver High
side
0 V
Low
side
S witch
5 V
0 V
2
1
!