| comm info |
This table contains the following information:
| Field Number |
Field Name |
DE Type |
Possible Values |
| 0 |
key up delay |
rtINT16 |
-32,767 to 32,767 (msec) |
| 1 |
key down delay |
rtINT16 |
0 to 32,767 (msec) |
| 2 |
channel clear delay |
rtUINT16 |
0 to 65,535 (msec) |
| 3 |
turnaround delay |
rtUINT16 |
0 to 65,535 (msec) |
Where:
| Field Name |
Description |
| key up delay |
The desired time to wait (in milliseconds) after
asserting RTS (request to send), before sending data. If the value
is 0 (zero), no RTS is asserted. If the value is greater than zero,
the host will wait that number of milliseconds, after asserting RTS,
before beginning transmission, regardless of the value of CTS (clear
to send). If the value is less than zero, the host will wait until
either the CTS signal is received, or the specified number of
milliseconds has expired before transmitting. If the specified time
expires before CTS is received, the transmission fails. |
| key down delay |
The desired time to wait (in milliseconds) after the
last data character has been sent, before resetting RTS (request to
send). This should be a positive number; if the value is negative,
the minimum time of rtNap() is used (see Section 3 of the RTAP
Reference Manual for details). |
| channel clear delay |
The desired time to wait (in milliseconds) for the DCD
(data carrier detect) line to clear before asserting RTS. If this
value is zero, the DCD line will be ignored. If the value is
positive, the host will wait the specified number of milliseconds
for the DCD to clear before asserting RTS. If the DCD line has not
cleared before the specified time has expired, the transmission
fails. |
| turnaround delay |
The desired time to wait (in milliseconds) after data
has been transmitted in either direction, before a transmission in
the opposite direction is initiated. This time must be at least the
sum of the "channel clear delay", "key up delay" and "key
down delay". |
![[note]](../Images/noteicon.png) |
This table's information is only used if this table is
not specified in the scan device point. |
|
| rs232 |
This table contains the following
information:
| Field Number |
Field Name |
DE Type |
Possible Values |
| 0 |
baud rate |
rtUINT16 |
50 to 19200 (bits/sec.) |
| 1 |
data bits |
rtUINT8 |
7 or 8 (bits) |
| 2 |
stop bits |
rtUINT8 |
1 or 2 (bits) |
| 3 |
parity |
rtUINT8 |
0=none, 1=odd, 2=even |
| 4 |
reserved |
rtUINT8 |
|
Where:
| Field Name |
Description |
| baud rate |
The transmission rate of the communication line in
bits per second. |
| data bits |
The number of significant bits within a transmitted
character or byte. This should always be set to 8 according to the
protocol manual. |
| stop bits |
The number of bits indicating the end of a transmitted
character. |
| parity |
The type of parity used for verifying correct
communication at the character level. Parity can be either even,
odd, or none. If parity is specified, and a parity error occurs,
then the character is ignored. This will cause a communication
error. |
|
| time sync |
This attribute is used by the scan task at
initialization time to determine if the scan task should send a Time
Delay request to the remote device. This request establishes the
message turn around time which is used to provide an offset for
relative time calculations for objects that require it. If this
attribute is zero, then no time delay measurement is attempted. If
this attribute is greater than zero, a delay measurement will be
attempted. If successful, the value will be set to one, if it fails,
the value will be changed to two. |
| master stn address |
Specifies the address for this master |
| max data size |
Specifies the maximum number of bytes to
be sent in a single DNP packet; which includes the application level
frame and any object frame and data. A non-zero value imposes a size
limitation. Regardless of the value of this attribute, at least one
scan record will be formed into a message. This attribute can be
used to limit the outgoing packet if any remote device(s) has a
maximum fragment size that it can receive.
![[warning]](../Images/warnicon.png) |
Regardless of the value of this attribute, at least
one scan record will be formed into a message if optimization is
disabled and one object will be formed into a message if
optimization is enabled. |
|
A minimum value of four is silently enforced. |
|
This limit is only imposed on data sent
to the remote device, not data received. |
|
| modem |
Specifies whether this communication port
is connected through a modem or not. |
| increment app seq |
Specifies whether the application sequence
number is incremented with each message sent to the RTU or not. |
| test link fails |
Specifies whether the scan input records
and scan input status are set to failed if the test link datalink
message fails. The default if this attribute does not exist is zero. |
| dial string |
Specifies the chat script used for talking
to the modem. This attribute is only used if "modem" is set
to one. The chat script is a series of expect-send pairs separated
by white space. The following special sets of characters are treated
specially when preceeded by a double backslash:
| Character(s) |
Description |
| d |
delay for two seconds |
| p |
delay for 0.25 seconds |
| n |
line feed |
| r |
carriage return |
| t |
tab |
| s |
space |
| T |
replaced with phone number to dial |
|
Control characters can be sent by
preceeding the character with a caret.
In addition to the above special characters, it is possible to
set a timeout value for receiving a response from the modem within
the string using the TIMEOUT value string.
The value is specified in seconds and will be used
until the next TIMEOUT token.
Embedded expect-send pairs can be put into the expect string by
using a dash as a separator.
Example:
TIMEOUT 5 \"\" AT OK-AT-OK \\dATDT\\T TIMEOUT 60 CONNECT
Sets initial timeout to five seconds, expects nothing, sends AT,
expects OK, but if it doesn't get it, will send AT and expect OK,
pauses for two seconds, sends ATDT followed by phone
number, and waits sixty seconds for the CONNECT string.
|
|
| hangup string |
Specifies the string that will be sent to
the modem to hang it up. For example, +++ATH0. |
| abort strings |
Specifies a set of strings that will be
returned from the modem when the dial fails. For example,
|
| socket |
Specifies whether the scan task should use
a serial connection (0), a TCP/IP socket connection (1), or a UDP
socket connection (2). |
| socket info |
Specifies the host and service name to use
when making a socket connection. This attribute is only used if "socket"
is set to one or two. The entry to use is specified in the "socket
index" attribute. This table contains the following:
| Field Number |
Field Name |
DE Type |
Possible Values |
| 0 |
host name |
rtBYTES8 |
(see below) |
| 1 |
service name |
rtBYTES12 |
(see below) |
Where:
| Field Name |
Description |
| host name |
Valid host name. |
| service name |
Valid service name from /etc/services.
The socket number specified should be specified using tcp (eg. dnp_sock
19000/tcp) if the socket is set for TCP/IP or udp (eg. dnp_sock
19000/udp) if the socket is set for UDP. |
|
| socket index |
Specifies the index into the "socket info"
table of the entry to use. Only used if "socket" is set to one or
two.
|
This attribute can also be located in the scan device
point if the "socket" is set for UDP/IP (2). This allows
individual scan devices to be failed over separately for a UDP/IP
connection. |
|
| process name |
Specifies the RTAP name that this scan
task will run as. This is useful for debugging purposes when there
are more than one DNP 3.0 communication port. |
| messages |
Specifies the value to write and the
database address to write to, when a specified message type is
received. This table contains the following:
| Field Number |
Field Name |
DE Type |
Possible Values |
| 0 |
msg type |
rtUINT32 |
(see below) |
| 1 |
database addr |
rtDB_XREF |
(see below) |
| 2 |
value |
rtDOUBLE |
(see below) |
Where:
| Field Name |
Description |
| msg type |
Specifies the message type (see rtMsgSend(3))
that this record is for. |
| database addr |
Specifies the database address that the
value should be written to. |
| value |
Specifies the value to write to the
database address. Note that the value will be coerced into the
appropriate data element type before being written. |
|
| primary |
Specifies whether this scan task acting
as the primary scan task or the backup scan task. In backup mode,
the scan task will not perform any of the following:
- polling
- force polls
- send out time syncs
- enable/disable unsolicited messages
- send out warm/cold restarts
- send out confirmation messages
The backup scan task will however, send out write requests.
|
| enable unsol reset |
Specifies whether the scan task will automatically
send out enable unsolicited messages when the restart IIN bit is
received from the RTU. A value of one, will enable unsolicited
messages to be sent automatically. |
| max recv size |
Specifies the maximum number of data bytes
in the response message. If the request would cause the response to
exceed this limit, the request will be broken down into multiple
requests. Note that vectors will not be broken down. This
attribute can be located at the scan device point as well in which
case it will override the comm port point's value. If this value is
zero, response size will not be checked. |
| test link interval |
Specifies the frequency, in seconds, that
a datalink test link message will be sent. A non-zero value will
result in a timekeeper interval request. |
| reply timeout |
The number of milliseconds that the scan
task will wait for a reply from the remote device before retrying
the communication. If a value of zero is specified, it will wait
forever. This timeout is used at the data link layer of the DNP
protocol. See message
timeout for a timeout value at the application layer. |
| retry count |
The number of times you want the scan task
to retry communication with an enabled remote device before
registering a communication failure. This retry count is used at the
data link layer of the DNP protocol. See message
retries for a retry count at the application layer. |
| debug device |
UNIX |
The device file where debug information is
to be printed. The full path must be provided; for example "/dev/ptyqf".
In addition to a device file, the following key words are
recognized: "stdout" and "stderr"; which
send debug information to the specified file pointer.
|
If a pseudo-terminal device is to be used, specify the
master device; otherwise the driver will be hung on the open
waiting for the master side of the pseudo-terminal to be opened. |
![[caution]](../Images/cauticon.png) |
If a pseudo-terminal device is used, the scan task must
be started before any process tries to open the slave
device; otherwise no debug information will be printed. |
|
| Windows |
This specifies a "named pipe" that will
be created on the server machine. Client applications can then make
connections to this "named pipe" to receive debug information. A
separate thread is created to handle each client. There is a maximum
of six client connections allowed. Additional clients trying to
connect will fail.
Since this is a "named pipe", clients can connect
from other machines on the network.
|
Depending on the network connection speed, some debug
data may be lost. Tests here, show that for a full 10 Mbit/sec
connection, no data is lost. |
|
This can also specify the name of an existing file. In
this case, the debug information will only be sent to the
file. Use this when you have a fast network connection with lots
of data.
See the tesserNet Scan Debug Utilities for freely distributable
client applications.
|
|