Woodward MRM4, Руководство пользователя, Страница: 186 / 460

Communication Protocols
Communication Protocols
SCADA Interface
X103
Device Planning Parameters of the Serial Scada Interface
Parameter Description Options Default Menu path
Protocol Caution! Changing the
protocol will cause a
restart of the device -,
Modbus,
IEC60870-5-103,
Profibus
Modbus [Device planning]
Global Protection Parameters of the Serial Scada Interface
Parameter Description Setting range Default Menu path
Optical rest position Optical rest position Light off,
Light on
Light on [Device Para
/X103]
Modbus ®
Modbus
Modbus ® Protocol Configuration
The time-controlled Modbus ® protocol is based on the Master-Slave working principle. This means that the
substation control and protection system sends an enquiry or instruction to a certain device (slave address)
which will then be answered or carried out accordingly. If the enquiry/instruction cannot be answered/carried out
(e.g. because of an invalid slave address), a failure message is returned to the master.
The Master (substation control and protection system) can query information from the device, such as:
•
Type of unit version;
•
Measuring values/Statistical measured values;
•
Switch operating position (in preparation);
•
State of device;
•
Time and date;
•
State of the device’s digital inputs; and
•
Protection-/State alarms.
The Master (control system) can give commands/instructions to the device, such as:
•
Control of switchgear (where applicable, i.e. each acc. to the applied device version);
•
Change-over of parameter set;
•
Reset and acknowledgement of alarms/signals;
•
Adjustment of date and time; and
•
Control of alarm relays.
Page 186 EN MRM4 01/11