1MRS755225
Transformer Terminal
Technical Reference Manual, General
RET 54_
85
5.1.14.
Time synchronization
The internal clock of the RET54_ relay unit can be set from different sources:
1. The time can always be given manually from the front panel
(
Configuration\General\Date
,
Configuration\General\Time
).
2. The time synchronization can also be set externally, either by a communication
protocol or by a binary input. The parameter (
Configuration\
General\Timesync source
) is used for selecting the source for external
synchronization. The parameter has two states
Comm. channel
(default) and
Input X5.2/1,2
.
When
Comm. channel
is selected, the system clock is adjusted according to time
synchronization messages from any of the supported communication protocols.
When parallel communication is used, the user has to make sure that
synchronization messages are received from only one communication channel.
When
Input X5.2/1,2
is selected, the relay expects a pulse train on
the X5.2/1,2 binary input with a period of either one minute or one second. The
system clock will be round to the nearest whole second or minute, depending on the
period of the pulse train, on the rising edge of the input. If synchronization on falling
edge is desired, the input can be inverted by setting the parameter
Configuration\BIO1 [5]\Input inversion\Input 12 invert
to
Enabled
. If time synchronization messages are also received from a
communication protocol, they are accepted, but only the year-month-day-hour-
minute-second part is written to the internal clock. Therefore a communication
protocol such as SPA can be used to set the internal clock with a coarse time and
simultaneously the binary input is used to fine-tune the accuracy.
Note that the clock of the protocol master and the pulse train on the binary input must
be synchronized, with a deviation always less than 500 ms, otherwise the internal
clock of the relay will make sudden one second jumps in either direction.
5.1.15.
Display panel (HMI)
The transformer terminal is provided with either a fixed display or an external
display module. The external display module requires a separate voltage supply
from a common source with the main unit (refer to Section “Auxiliary voltage” on
page 36). For more information about the rated input voltages, refer to Table 5.2.1-
2 on page 90. A special cable (1MRS120511.002) delivered with the transformer
terminal is needed for communication between the terminal and the external display
panel. This standard cable is 2 meter in length. The cable is also available in an
optional 1 / 3 meter version. (Ordering number 1MRS120511.001 /
1MRS120511.003)
• Graphical LCD display, with the resolution 128 x 160 pixels, consisting of 19
rows divided into two windows
• main window (17 rows) providing detailed information on MIMIC, objects,
events, measurements, control alarms and parameters of the terminal
• assisting window (2 rows) for terminal-dependent protection indications and
alarms, and for general help messages
• three push-buttons for object control
