Abstract: Introduced the current telecommunication engine
room equipment each kind of centralized monitoring system, strings
together the mouth programming the main method as well as carries on
the cross platform through the terminal server to each kind of string
mouth equipment, the cross application system carries on the
networking the plan.
Key word: Centralized monitoring system, string mouth
networking, string mouth programming, terminal server
1 introduction
Current in a fixed telephone operation business
sub-bureau (end bureau) in engine room, the main equipment has the
program controlled switch, the transmission facility, 配线? the
subscriber's loop test facility, the power source air conditioning
equipment and so on. In order to realize the management
automation and or the few people value defends to engine room nobody,
the telecommunication company has established several sets in view of
the above equipment centralized monitoring system, enables the
attendant to be allowed to monitor these equipment in the central
engine room the movement situation, and carries on the operation
maintenance to them, like local telephone network management system,
power equipment and environment centralized monitoring system, 112
centralisms test system and so on. Because in engine room these
equipment usually all are carry on the correspondence through the
string mouth, therefore regarding establishes a centralized monitoring
system, how realizes these equipment string mouth networkings and the
string mouth programming, is an extremely essential work.
2 strings mouths programming method and application
At present, carries on the device control to the string
mouth programming, mainly has two methods: One directly carries
on the programming to the string mouth, two is transforms through the
network equipment into the network programming.
2.1 directly to string mouth programming
Under the UNIX environment with the C language
programming, is same with other equipment, to the string mouth
operation, is through realizes to the equipment document programming.
The UNIX system each string mouth achievement or many equipment
documents, deposits under the /dev table of contents, we may look like
to the ordinary document same programming, realizes to the string
mouth control, take the under this young Duan code as the example:
#include /* Standard input/output definitions */
#include /* String function definitions */
#include /* UNIX standard function definitions */
#include /* File control definitions */
#include /* Error number definitions */
#include /* POSIX terminal control definitions */
Main ()
{
Int fd; /* File descriptor for the port */
Int n, res;
Char buf [ 255 ];
Fd = open (/dev/tty1a, O_RDWR | O_NOCTTY | O_NDELAY);
If (fd == -1)
{
/* Could not open the port. */
Perror (open_port: Unable to open /dev/tty1a -);
}
Else
Fcntl (fd, F_SETFL, 0);
... ...
Res = read (fd, buf,,255);
... ...
N = write (fd, ATZ\r, 4);
If (n < 0)
Fputs (write () of 4 bytes failed! \n, stderr);
... ...
Close (fd);
}
This section of code has manifested under the UNIX
environment to the document and equipment open, write, read, the close
programming standard, certainly, also can involve in the concrete
application to many details questions.
Application example: Local telephone network management
system. The Nanning telecommunication company at present uses
the public opinion switchboard network management and the centralized
monitoring system (hereafter refers to as network management system)
is NOMA2.0 which develops by the original Ministry of Posts and
Telecommunication software center. Although more and more many
switchboards provide based on X.25 or the TCP/IP correspondence
connection, the traditional RS232 connection or one kind main turns on
the way, like EWSD OMT mouth, S1240 MMC mouth and MPT mouth and so on.
The network management system through the pretage machine
receive switchboard report, sends each kind of instruction to the
switchboard under. The pretage machine installment in the
network management center engine room, the usual disposition is the
PII350 microcomputer, the operating system is SCO UNIX5.04/5.05, each
pretage machine is loaded with together MOXA Smartio the C168H/PCI
string mouth card, may or simulates the special line and various
sub-bureaus' 8 switchboards connection through the DDN special line is
connected, with the switchboard correspondence is through the direct
read-write string mouth realization, in this foundation in realization
to switchboard telephone traffic and warning management, centralism
maintenance operation. At present we used this way to turn on
more than 30 switchboards, nearly 100 ports.
2.2 through network to string mouth programming
Is (or is called network correspondence server) to the
string mouth programming another commonly used programming method with
the terminal server, will string together the mouth transformation
will be a network port, through to network port programming
realization to string mouth equipment control. Under the UNIX
environment, carries on the network programming, the Socket program
library is most popular API (Application Program Interface), strings
together network port usual achievement server which the mouth
transforms (server), the application procedure takes the customer end
(client). The customer end programming is through transfers
socket the system function realization, generally transfers the
process as follows: Transfers socket () to found a socket port,
transfers connect () to connect the server, when alternately controls,
transfers write () to transmit the request, transfers read () to
receive the reply, transfers close () to finish the connection, the
specify which the function transfers please refers the correlation
data.
Application example: 112 centralisms tests system.
The Nanning telecommunication company's 112 centralisms accept,
the test and the management system management system (hereafter refer
to as 112 systems) are reach the company by the Guangzhou Switzerland
to develop, main function is carries on the test automation to the
subscriber's loop. The test function by installs 测试?
completes in the sub-bureau, 测试?provides a RS232 string mouth,
in sets special line MODEN and the digit dialing MODEN connection, may
will choose DDN, the special line or the digit dialing way according
to the scene actual condition 测试?the company to 112 central
terminal servers. Connects MOXA CN2100 series Async Server (IP
address position 134.201.9.253) the P1 mouth is an example, supposes
PORT 01 OP_mode for reverse telnet (RTELNET) the way, in disposes in
Line to establish the suitable baud rate (Speed), the data position
(Bits), stops the position (Stop), the verification (Parity) and so on
the parameter, like this we on a string mouth transformation are a
134.201.9.2534001 TCP/IP port, may straight take over the use of
telnet 134.201.9.2534001 to test the port whether corresponds
normally. 112 systems servers (Digital the AlphaServer 4,100
small machines, operating system is Digital UNIX V4.0D) on test
automation procedure through to this port programming, realizes to
用户线test. As a 112 systems part, 112 simulations test order
also is selects this connection method and the programming method,
what is different is the simulation test order connection server is
not 测试? but is the switchboard port, through switchboard
man-machine order realization to 用户线test. At present, the
Nanning telecommunication company 112 systems already have installed
more than 60 sets of test facilities (including 测试?and
simulation test port), may carry on the centralism test automation to
more than 700,000 fixed telephones users' telephone channel.
3 uses the terminal server the string mouth networking plan
Above two kind of networkings and the programming plan
have a common ground, all will be through the certain transmission
method (DDN, simulates special line, digit dialing and so on) strings
together the mouth to connect the central engine room on the
equipment, again will carry on the programming control. This
kind of plan has a not good place, is if has many strings mouth need
networking, not only takes the massive transmissions resources,
moreover the wiring also has the certain difficulty, therefore has the
necessity to seek some new networking methods.
At present, the Nanning telecommunication company has completed
the cover entire this network the computer network, in this
foundation, through installs the terminal server in the sub-bureau to
carry on the string mouth networking is simple and the reliable plan.
Through the network to the string mouth programming, installs
the terminal server in the central engine room perhaps in the far-end
sub-bureau in the programming no difference, so long as carries on
some route dispositions, guaranteed the server and the far-end
sub-bureau's terminal server network was unobstructed may.
Regarding directly carries on the programming to the string
mouth, may use UNIX fixed tty software, this procedure through the
false tty equipment is Unix the main engine assignment fixed tty
connection, said to the application procedure, this tty connection and
the ordinary local string mouth no difference, Moxa Async Server fixed
the tty disposition is quite simple, the detailed step please refer
the product the use guide. In the network management system, we
in pretage machine on move fixed tty software, port carries on the
networking test in the far-end sub-bureau to EWSD the switchboard OMT,
the effect with receives the central engine room pretage machine
string mouth through the DDN direct company to embrace no difference.
Thus it can be seen, installs the terminal server in the
sub-bureau carries on the string mouth networking is completely
feasible, its advantage also is obvious, first, may reduce rents
transmits the line quantity, next, obtains the full simplification in
the central engine room wiring, more importantly, these improvements
does not need to change the application procedure, the development
personnel may continue to use the programming method which oneself is
familiar with. Certainly, said regarding the supervisory system
that, this request must be high from the central engine room to
sub-bureau's network reliability, simultaneously must have the
reliable safe authentication method visit to the port.
In the practical application, we have already installed the
terminal server in more than 10 fars-end sub-bureaus', at present
mainly provides to 112 测试?and the switchboard port networking.
Take the high new sub-bureau as the example, we have installed
Moxa Async Server in the engine room (model are CN2108), turns on
测试? two S1240 MMC mouth, two EWSD OMT mouth, PAD Vanguard 200
(one kind EWSD X25 the LINK transformation is OMT mouth equipment)
control port. Some point needs to pay attention, when the S1240
MMC mouth each time connects, needs to send a break signal to carry on
the activation, some terminals server cannot send out the break
signal.
Now the terminal server function more and more consummates, may
support the different computer platform and the operating system, may
nimbly for the different application system disposition port, for
example we when establish a port as the reverse telnet pattern, no
matter is UNIX or the windows system, the application procedure so
long as follows the TCP/IP agreement, may to its meet the equipment to
carry on the control; Except UNIX fixed tty software, but also
may through the corresponding driver, transfer the port Windows the NT
solid port (Real COM Port). Network management system, 112
systems introduced which except above, but also has the power
equipment and the environment centralized monitoring system, some
companies have also established the optical fiber supervisory system,
配线?the supervisory system and so on, all involves the string
mouth equipment networking the question, although these system
relative independences, the engine room distribution position is
different, the developer and the use department is not same, but we
may use the terminal server to establish a string mouth correspondence
network, provides the transparent string mouth for the different
application system to turn on the service, this not only may save the
massive transmissions resources, but also may carry on the network to
each system to optimize, simplification wiring, The reduction to
transmits the line maintenance work load.
4 concluding remark
Now, many telecommunication companies all have
established cover majority engine room WAN, according to ours use
experience, when a sub-bureau has many strings mouth needs to turn on,
in the far-end sub-bureau installs the terminal server not to lose is
an economy is practical and the also reliable networking plan.
At present, except more than 10 sub-bureaus which already
completes, we plan in each sub-bureau (including all county seats
sub-bureau and partial modules bureau) install the terminal server,
gradually establishes a special string mouth correspondence network,
and shears some application systems ports receives this network to
come up.
Reference:
1st, "Serial Programming Guide for POSIX Operating Systems"
Michael R. Sweet
Http://www.easysw.com/~mike/serial/serial.html
2nd, "UNIX Technology - Network Application", author:
Shen Zhishen, electronics industry publishing house publication |
