ABB 620 Series ANSI, Manual

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1MAC052634-MB D
Section 3
Vendor-specific implementation
615/620 series ANSI 43
Communication Protocol Manual
Method 1: Synchronization in one step
The real-time clock structure registers should be written in one multiple registers preset
request (function 16) by a Modbus TCP/IP client or by a serial interface master. The IED's
Modbus address or the Modbus broadcast address can be used with the serial interface. If
the clock is written in one step, the write value of the control register is not checked by the
IED.
Method 2: Synchronization in three steps
1. The client reserves the time synchronization by writing value “1” to the control
register. If necessary, check that the reservation value is zero at the beginning. If the
time synchronization writing is already reserved by another client, the IED returns
the exception response 03.
2. The client writes the time structure to the IED. This can be done in one transaction
or alternatively each register can be written separately.
3. The client sets the clock by writing “2” into the control register. When the value “2”
is written, the timesync registers are latched onto the IED's internal clock and the
reservation of the control register is released.
There is an internal timeout for the clock setting. The time synchronization reservation is
released if the clock is not set within two minutes. The client can abort the time
synchronization at any time by writing “0” into the control register. In that case the
real-time clock is not set at all.
Other Modbus clients can read the currently running real-time clock even if the time
writing is reserved by another client.
3.3.12 Device information
The IED's device information can be read from the Modbus registers.
The Modbus device information is based on the IED's internal IEC 61850 device
information model. All internal descriptions are coded as ASCII strings. The Modbus
device information ASCII string includes the information from the IED:
• IED model (max. 12 characters)
• IED type (max. 6 characters)
• IED serial number (max. 12 characters)
• IED location information (max. 34 characters)
• CPU card SWand HW revision numbers
The Modbus broadcast address cannot be used with the synchronization
method 2.
If the information data are in practice shorter, the trailing registers in the
response are filled with the value “0”.