Introduction; Features Of The Aps; Category; Overview - Cedes APS Installation And Operation Manual

APS

4. Introduction

The Absolute Positioning System (APS) determines the
absolute position and velocity of the elevator car by
reading a fixed installed code tape in the hoistway. It
transmits this safety related information using a specified
interface e.g. CAN2.0A or RS485 to the downstream
processing unit (e.g. elevator controller).
The APS system consists of the APS sensor, the code tape,
the guide clips and position indicator clips. The sensor is
mounted on the elevator car and the code tape is mounted
with the clips within the elevator hoistway.
The information of the absolute position is encoded
on the code tape. The APS sensor is based on a dual
camera system which scans the code tape with its own IR
illumination. The sensor evaluates the position information
from the code tape and also calculates the velocity of the
elevator car using two positions at two different times. The
position and velocity information is transmitted over the
interface to the downstream processing unit. The APS is
certified according to SIL 3 IEC 61508.
Depending on the implementation, the APS sensor can be
used to compensate for building compression relative to
the absolute hoistway position as well as detect the floor/
door zone. To do so, a special clip, the position indicator
clip, is used to mount on the code tape in the hoistway. If
the clip is detected by the APS sensor, the corresponding
bit is set to high and this information is transmitted as part
of the protocol to the downstream processing unit.
In order to make use of functions such as detection of
building compression or floor/door zone detection,
the downstream processing unit must be capable of
processing this information and set to do so.
4.1

features of the APS

• Position and velocity output
• Absolute position up to 1,500 m with a resolution of
0.5 mm
• Velocity up to 20 m/s with a resolution of 1 mm/s
• Integrated reading of markers for building
compression compensation, no additional sensors
needed
• Level detection using position indicator clips
• Very robust system due to high light reserve and dual
camera reading
• Insensitive to dust and smoke
• CAN or RS485, (customer specific interface on
request)
• SIL 3 certified
4.2

Category

SIL 3 certified for
• safely detecting the position
• safely calculating the velocity
• safely transmitting the data to the downstream
processing unit
For more details refer to the APS Safety Manual (Part. No.
113 317).
4

5. Overview

APS sensor
Connection to the
downstream
processing unit
figure 1: APS system overview
Figure 1 shows the necessary components to build an APS
system with building compression compensation.
5.1

Type description

a – b – ccc – d – ee – ff/gg – h/i – j – k, cable length in m
APS type
a : S Safety
Hardware type
b : 2 2 reading heads
Interface type
ccc : CAN CAN
485 RS485
Interface channels
d : 1 1 channel
2 2 channels
Communication protocol
ee : SP CAN standard protocol
NP CAN new protocol
RS RS485 protocol
Data timing multiplier
∙ Channel 1
ff : 01 1 × 5 ms = 5 ms
∙ Channel 2
gg : 01 1 × 5 ms = 5 ms
Data rate
∙ Channel 1
h : A 250 kbit/s
C 230.4 kbit/s
D 115.2 kbit/s
X Not available
∙ Channel 2
i : A 250 kbit/s
C 230.4 kbit/s
D 115.2 kbit/s
X Not available
Mounting
j : M Metric
U UNC
Plug
k : R RJ45
, cable length in m
0.5 ... 5 m
figure 2: Type description
Camera A
(field of view)
Camera B
(field of view)
Position
indicator clip
Code tape
Guide clip
(only RS485)
(only CAN)
(only CAN)
(only RS485)
(only RS485)
(only CAN)
(only RS485)
(only RS485)
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