Operation; Startup; Output Signals And Accuracy; Rs422 Incremental Position Output - Bosch Rexroth CIMS Mk IV Instruction Manual

5. O
PERATION
5.1. S
TARTUP
Before the cylinder with CIMS is put into operation make sure to follow the startup procedure as
described below.
1. Check connections before applying power to the CIMS. The connections are polarity
reversal protected, however components can be damaged by improper connections and /
or overvoltage.
2. Apply power to the CIMS. At first power-on after installation onto the cylinder, the accuracy
of CIMS Mk IV is limited to maximal 2.5mm for the first 10mm of movement of the piston
rod, as the CIMS Mk IV automatic calibration needs this movement to compensate for
mounting tolerances and other influences from its surrounding. After 10mm, the calibration
is finished and the CIMS will function with the specified accuracy.
3. After replacing a CIMS, it is advisable to verify the output signals by moving the cylinder in
manual mode. Is the output corresponding with the actual movement/position of the
cylinder? If possible, read the diagnostic output to verify there are no warning or error
messages, see Section 5.2.2
5.2. O S
UTPUT IGNALS AND
Two output interfaces are available:
1. The main output is a RS422 incremental position output (see details in paragraph 5.2.1).
This quadrature encoder output provides incremental A and B pulses and also the inverted
A and B pulses according to the EIA RS-422 format.
2. A RS485 diagnostic output (see details in paragraph 5.2.2) with MODBUS protocol.
5.2.1. RS422 I
NCREMENTAL
The position output is a quadrature encoder output with incremental A and B pulses and also the
inverted A and B pulses according to the EIA RS-422 format.
The RS-422 output format is chosen for its extreme insensitivity for EMI (Electro Magnetic
Interference) and its capability to transmit the displacement information over cable lengths up to at
least 200 meters.
The RS-422 incremental output gives out 1024 pulses/cm
in X1 mode, according Figure 19. The sequence of A and
B pulses is determined by the direction of movement of
the piston rod. The A pulse rising from "0" to "1" before
the B pulse rises from "0" to "1" means the cylinder is
extending. The B pulse rising from "0" to "1" before the A
pulse rises from "0" to "1" means the cylinder is
retracting.
The incremental position output has the following
specifications:
 Non-linearity:  ±1 mm (after automatic calibration, see Section 5.1).

Hysteresis and reproducibility: typical ±0.05 mm (after automatic calibration, see Section 5.1).
F 037 300 069 (2013.05.21)
A
CCURACY
P O
OSITION UTPUT
23
Figure 19: RS422 incremental output signal.