Display Panel (Hmi) - ABB REX 521 Technical Reference Manual, General

REX 521
4.1.14.
40
Protection Relay
Technical Reference Manual, General
"Net Messages" state
The parameter should be in the "Net Messages" state if the time synchronization is
taken from one of the following sources:
SPA bus
• Time synchronization is received from the SPA master device.
IEC 60870-5-103 bus
• Time synchronization is received from the IEC 60870-5-103 master device.
LON bus in the following cases:
• Time synchronization message is received from the SNVT_Timestamp input
network variable.
• Time synchronization message is received from the nv_warning/nv_clock
input network variables.
Some additional comments:
The SNVT_Timestamp network variable selector is 0x2FF5 (fixed).
The nv_warning and nv_clock selector values are 0x2FFE and 0x2FFF
respectively (also fixed).
"X3.1.2 Input" state
Synchronization is received from the digital input DI9. The input can act either as a
minute or a second synchronization input depending on the setting of the parameter
Sync.rounding. Furthermore, it is possible via the parameter
Sync.trigg.slope to set the pulse edge (positive or negative) which triggers
the synchronization.
Accuracy
When there is no external synchronization, the roaming time is better than 3 ms/min.
It is recommended that the relay is synchronized once a second in order to achieve
optimal accuracy.

Display panel (HMI)

The front panel of the relay includes:
• A 2 X 16 character LCD (2 rows)
• Three protection indication LEDs
• Eight alarm LEDs
• Arrow buttons for menu navigation
• Optically isolated serial communication port
Additional features of the display:
• Contrast adjustment with temperature compensation
• Backlight control
1MRS 751108-MUM