2. Product characteristics
The PSU Evaluation Unit is a safe position evaluation unit for implementing functions of limit switches,
inspection limit switches, time-delayed limit switches, Unintended Car Movement (UCM) as well as for
the safe bypass of the safety circuit in the area of the doors in case of premature door opening/relevel-
ling of elevator systems according to EN81-20.
The overall system PSU01 consists of two devices, the Ants LES01 (Linear Encoder Safe) and the
PSU Evaluation Unit (Position Supervisor Unit) described here. The PSU01 is connected via a free
CAN-bus to an external compatible control, a CANopen terminal or an external programming device,
which is used for parameterising the safety functions. The parametrisation procedure is not a part of
these operating instructions. In this respect, reference is made to the separate programming manual
or the respective manual of the compatible control.
The PSU01 receives corresponding parameters or reset commands from one of these devices via the
free CAN bus (Port X3) and outputs information about the position, state, etc. to these external devi-
ces as well as to elevator controls. The pure positioning output is also optionally supported via SSI.
The PSU Evaluation Unit and the Ants LES01 are certified as a complete system and may only be
operated together. They are factory-identified by a Set.ID. Ants LES01 safely provides the absolute
positions of the elevator plant via a second private CAN bus and forwards them to the PSU Evaluation
Unit (Port X2). Ants LES01 is moreover certified and available as a standalone product.
2.1 Function of the PSU01
The PSU01 fulfils the following requirements for the state-of-the-art elevator system:
• Limit switch emulation
• Inspection limit switch emulation for reduced shaft head / shaft pit
• Safety circuit for bypassing the door contacts
• Unintended Car Movement (UCM)
• Time-delayed limit switch emulation
• Overspeed pre-tripping
• Door zone emulation for forwarding the information to an optional external UCM unit
The PSU01 fulfils the requirements according to EN81 by:
• The one-time teaching of all stops (performed during commissioning)
• Safety relays to open the safety circuit
• Safety relays for door bypass
• Inspection input query
2.1.1 Limit switch emulation
The emergency limit switches are simulated according to EN81-20 Safety function 5.12.2.
New stations must be at least 2 mm away from the taught limit switch positions.
EN - page 8 (R60953.0009 3)
The Ants LES01 as part of the PSU01 must be correctly commissioned
according to its operating instructions.