European Railway Agency
ETCS Driver's handbook

Limited Supervision (LS)

LS-[2021.L123].1The Limited Supervision (LS) mode enables the train to be operated in areas where trackside information can be supplied to realise background supervision of the train.

This mode cannot be selected by the driver. It can only be entered if ordered by trackside.

LS.APPApproaching an LS area (APP)

LS.APP-[2021.L123].1When the train is approaching a LS area, the Acknowledgement for Limited Supervision mode symbol (MO22) is displayed to the driver. The driver shall acknowledge the LS mode as indicated in the following section LS.ACK Acknowledge of LS mode (ACK).

MO22: Acknowledgement for Limited Supervision mode

If the LS mode is requested for the current location, the transition to LS mode is performed immediately and the Limited Supervision symbol (MO21) is displayed.

If the LS mode is requested for a further location, the beginning of the LS area is supervised as an EOA with no release speed until the driver acknowledges the request for limited supervision mode.

LS.ACKAcknowledge of LS mode (ACK)

LS.ACK-[2021.L12.N].1When the Limited Supervision mode symbol (MO22) is displayed, the driver shall acknowledge the LS mode according to non-harmonised rules.

LS.ACK-[2021.L1.T].1To acknowledge the LS mode, the driver shall press the button as indicated in Figure LS.ACK-[2021.L1.T].F1.

Figure LS.ACK-[2021.L1.T].F1: Acknowledgement for Limited Supervision mode button (touch screen technology)

LS.ACK-[2021.L23.T].1To acknowledge the LS mode, the driver shall press the button as indicated in Figure LS.ACK-[2021.L23.T].F1.

Figure LS.ACK-[2021.L23.T].F1: Acknowledgement for Limited Supervision mode button (touch screen technology)

LS.ACK-[2021.L1.S].1To acknowledge the LS mode, the driver shall press the button with a flashing frame associated to the MO22 symbol as indicated in Figure LS.ACK-[2021.L1.S].F1.

Figure LS.ACK-[2021.L1.S].F1: Acknowledgement for Limited Supervision mode button (soft key technology)

LS.ACK-[2021.L23.S].1To acknowledge the LS mode, the driver shall press the button with a flashing frame associated to the MO22 symbol as indicated in Figure LS.ACK-[2021.L23.S].1.

Figure LS.ACK-[2021.L23.S].1: Acknowledgement for Limited Supervision mode button (soft key technology)

LS.ACK-[2021.L123].1When the driver acknowledges LS mode, or the train reaches the beginning of the limited supervision area, the mode changes to LS mode.

LS.ACK-[2021.L123].2Once inside the limited supervision area, if the driver has not acknowledged the transition to LS mode within 5 seconds after the change to LS mode, the service brake command is triggered.

The brake command is released when the driver acknowledges the change to LS mode, unless the command was triggered for another reasons.

LS.ACK-[2021.L123].3If when entering the LS mode, the train speed is higher than the LS mode speed limit the brake could be immediately triggered, independently of the acknowledgement of the driver.

LS.RUNRunning in LS (RUN)

LS.RUN-[2021.L123].1When limited supervision mode is active, the Limited Supervision symbol (MO21) is displayed.

MO21: Limited Supervision mode active

LS.RUN-[2021.L123.N].1While the Limited Supervision symbol (MO21) is displayed to the driver, the driver shall apply the non-harmonised rules.

The indications given to the driver by the ETCS on-board equipment do not substitute the observance of the line-side information. The driver must always observe the existing line-side information and National operating rules.

LS.RUN-[2021.L123].2The driver shall enter the Track ahead free information if requested as indicated in section OTH.TAF Track Ahead Free (TAF).

LS.RUN-[2021.L1.T].1The Lowest Supervised Speed within the Movement Authority is displayed in the area indicated in Figure LS.RUN-[2021.L1.T].F1.

Figure LS.RUN-[2021.L1.T].F1: Lowest Supervised Speed within the Movement Authority (touch screen technology)

LS.RUN-[2021.L23.T].1The Lowest Supervised Speed within the Movement Authority is displayed in the area indicated in Figure LS.RUN-[2021.L23.T].F1.

Figure LS.RUN-[2021.L23.T].F1: Lowest Supervised Speed within the Movement Authority (touch screen technology)

LS.RUN-[2021.L1.S].1The Lowest Supervised Speed within the Movement Authority is displayed in the area indicated in Figure LS.RUN-[2021.L1.S].F1.

Figure LS.RUN-[2021.L1.S].F1: Lowest Supervised Speed within the Movement Authority (soft key technology)

LS.RUN-[2021.L23.S].1The Lowest Supervised Speed within the Movement Authority is displayed in the area indicated in Figure LS.RUN-[2021.L23.S].F1.

Figure LS.RUN-[2021.L23.S].F1: Lowest Supervised Speed within the Movement Authority (soft key technology)

LS.RUN-[2021.L123].3The LS mode is exited when the front end of the train passes the end of the LS area.

LS.RUN-[2021.L123].4The following mode transitions can be triggered from LS mode:

  1. NP mode. Transition triggered when the ETCS on-board is powered off, see section OFF.PWR Power off the ETCS on-board (PWR).
  2. SB mode. Transition triggered when the desk is closed, see section OFF.CLS Close the desk (CLS).
  3. SH mode. Transition initiated either manually by the Driver, see section SH.MAN Manual entry into SH (MAN) or automatically by an order from the Trackside, see section SH.AUT Automatic entry into SH (AUT).
  4. FS mode. Transition usually initiated by order from the Trackside, see section FS.RUN Running in FS (RUN).
  5. SR mode. Transition is manually initiated by the Driver after selecting override, see section OVR.RUL Rules to pass an EOA (RUL).
  6. OS mode. Transition automatically initiated by an order from the Trackside, see section OS.APP Approaching an OS area (APP).
  7. NL mode. Transition manually initiated by the Driver, see section NL - Non-Leading (NL).
  8. UN mode. Transition usually initiated by an order from the Trackside, see section UN - Unfitted (UN). This transition also includes a transition of level initiated either manually by the Driver, see section LTR.TRS.DRV Level transition initiated by driver (DRV) or ordered by the Trackside, see section LTR.TRS Level transitions (TRS).
  9. TR mode. Transition automatically initiated by an order from the Trackside, see section TR - Trip / Post Trip (TR).
  10. SF mode. Automatic transition triggered in case of a fault, see section SF - System Failure (SF).
  11. IS mode. Transition triggered when the driver isolates the ETCS on-board equipment, see section IS.ENT Entering Isolation mode (ENT).
  12. SN mode. Transition usually initiated by an order from the Trackside, see section SN - National System (SN)). This transition also includes a transition of level either initiated manually by the Driver, see section LTR.TRS.DRV Level transition initiated by driver (DRV) or ordered by the Trackside, see section LTR.TRS Level transitions (TRS).
  13. RV mode. Transition initiated after the driver“s acknowledgement of the RV mode, see section RV.ENT Entry in RV mode (ENT)