Serial Optical And Rs485 Communication Channel Settings - Hitachi Relion 670 Series Communication Protocol Manual

Section 4
DNP3 parameters
tBrokenConTout determines how long a session is active after a TCP/IP connection has been broken.
After that time period the master session becomes inactive and events are not stored. If the parameter is
set to 0, events are stored until the buffers overflow.
tKeepAliveT determines, in seconds, how often the DNP3 master session sends keep-alive messages.
Default is 10s.
4.1.1

Serial optical and RS485 communication channel settings

RS485 specific communication channel settings, RS485GEN
Wiremode determines the wire mode if the device is configured for RS485. RS485 is a balanced serial
communication that can be used in two ways:
• Two-wire
• Four-wire
A two-wire connection uses the same signal for RX and TX, and is a multidrop communication with no
dedicated master or slave. This variant requires however a control of the output. The four-wire
connection has separate signals for RX and TX multidrop communication with a dedicated master and
the rest are slaves. No special control signal is needed in this case.
Operation selection for RS485 and optical serial communication,
OPTICALPROT and RS485PROT
ProtocolSel selects if the communication in RS485 and optical serial modes happens via DNP or IEC 103
communication protocol. It can be Disabled via Parameter Setting tool or local HMI.
DNP3.0 for optical RS-232 and EIA-485 communication protocol,
OPTICALDNP and RS485DNP
BaudRate specifies the baud rate on the serial.
DLinkConfirm determines when the stack should ask for link layer confirmations. Since DNP3 supports
breaking an application layer message into multiple link layer frames, set to the following based on the
desired operation for a specific communication session:
• Never - not for any frame
• Sometimes - only for multiframe message fragments
• Always - for all frames
tDLinkTimeout specifies the maximum amount of time to wait for a link level confirm if requested (that is,
if DLinkConfirm is Enabled). Even if DLinkConfirm is set to Never, this will be used for linktest frame and
request link status if they are sent.
DLinkRetries is the maximum number of link layer retries if data-link layer confirms time up.
tRxToTxMinDel is the minimum time (in seconds) after receiving a character, before another attempt to
transmit a character on this channel. This is generally useful when using a modem or some other
communication device that requires a minimum time between receive and transmit.
ApLayMaxRxSize specifies the maximum application fragment size received in octets.
26
The master subnet mask must not be changed unless the master gets its IP-address
dynamically assigned via, for example, DHCP. For details see,
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DNP3 TCP/IP mode
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DNP, 670 series
Communication protocol manual