DECODE IDM 50B User manual

DECODE
Multi-standard modem IDM 50B
User Manual v1.2n
http://www.decode.co.yu

1. INTRODUCTION
1.1 Modem Overview
IDM50B is a multistandard modem for asynchronous or transparent data transmission in 300-
3400 Hz voice band. For lower baud rates it uses binary frequency modulation techniques
(FSK), which make it highly immune to interference and noise and permit extensive voice-band
communication link utilization. For higher baud rates it uses QAM modulations with 4, 8 and
16 constelation points, depending of selected rate.
The modem supports CCITT V.29, R.38A, R.38B, R.37, R.35, V.23 and Cegelec 1200/600Bd
communication standards. Table of programmable channels (Figure 1.) depicts possible
utilization of audio band in FSK mode. In FSK mode the modem can operate in half or full-
duplex, point-to-point or point-to-multipoint mode, with receive and transmit channels
independently set. For V.29 mode, four-wire full/half duplex is default.
The modem employs advanced Texas Instruments 32-bit DSP technology, thus offering high
service flexibility through programmable features. Modem configuration is performed via
Hayes AT commands on separate DIAG serial port, available at front panel. AT commands
may be initiated from any asynchronous terminal application using RS-232 communication
interface. Additionally, for easy firmware upgrade, a bootstrap loader is provided using the
same DIAG serial port.
IDM50B is designed to be use in SCADA systems mainly based upon power utility
communication networks. Depending on selected mode, it can communicate through
specialized, private or leased lines, radio links and power lines (PLC).
Figure 1. Table of programmable channels in FSK mode
1.2 Mounting Types
IDM50B is available as a desktop modem or in two different types of standard 19'' rack:
1U rack with 1, 2 or 3 modems per rack;
3U rack with 10,12 or 14 modems per rack,
and additional blank front plates covering unused slots.
All connectors at the rear side are accessible at the back openings.
Please refer to Appendix A for details.
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 2

2. INTERFACES
2.1 Front Panel
RST Reset button is accessible on the front panel using a pin of diameter under 2 mm (pencil
tip, etc.). It re-initialise all modem functions. The modem must be reset immediately
on inconsistent operation appearance, before starting the maintenance diagnosis phase.
This reset, like a long duration power cut-off, has no effect on the status of
configurations previously loaded into the modem.
SET Set button is used for entering command mode (see “Entering Command Mode”
section), which allows modem configuration.
PWR In data mode PWR LED is ON when modem is power supplied and in proper function;
PWR LED is OFF in case of: power supply is not present or modem is in malfunction.
PWR LED blinks slowly (100ms / 1sec cycle) as an indication of command mode.
PWR LED blinks fast (100ms / 100ms cycle) when modem has locally initiated some
of the test modes. PWR LED blinks slowly (1sec / 1sec cycle) when modem is
remotely brought to some of the test modes.
TXD Transmit LED indicates data transmitted on TXD pin of RS-232 interface.
RTS Request to Send LED indicates state of RTS pin of RS-232 interface.
RXD Receive LED indicates data received on RXD pin of RS-232 interface.
DCD Data Carrier Detect LED indicates the presence of in-channel carrier with level higher
then predefined receive level.
Figure 2. IDM 50B Front panel view (desktop version)
2.1.1 DIAG – Command/Bootloader serial interface
This connector is a RJ45 8 pin female type connector. It provides the interface between
the modem and terminal unit in command mode and in firmware upgrade process. The
following table gives the allocation and function of each pin.
PIN ABB. FUNCTION DIRECTION
DTE-DCE
1 SW - BSL Switch – Bootloader selection input x
2 GND Signal Ground -
3 CTS Clear To Send ←
4 RD Received Data ←
5 TD Transmitted Data →
6 RTS Request To Send →
7 SW - RUN Switch – Run selection input x
8 SW - COM Switch – selection output x
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 3

2.2 Rear panel connectors
Three connectors are placed at the modem’s rear side (Fig. 3).
Figure 3. IDM 50B rear side (desktop version)
2.2.1 RS-232C / Data serial interface
This connector is a SUB D 9 pin female type connector with screw locking. It provides
the interface between the modem and remote terminal unit or data processing
equipment in data mode. The following table gives the allocation and function of each
pin.
PIN ABB. FUNCTION DIRECTION
DTE-DCE
1 DCD Data Carrier Detect ←
2 RD Received Data ←
3 TD Transmitted Data →
4 DTR Data Terminal Ready →
5 SG Signal Ground -
6 DSR Data Set Ready ←
7 RTS Request To Send →
8 CTS Clear To Send ←
9 RI Ring Indicator ←
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 4

2.2.2 Line / Analog interface
This connector is a SUB D 15 pin female type connector with screw locking, which
provides:
Interface between 2 or 4 wire analog line and the modem;
The fail relay output
On the same connector modem has interface intended for communications management
with a radio interface (squelch and alternate) which are not supported in current
firmware version. Figure below depicts analog line interface.
Fi
g
ure 4. Analo
g
line interface
2.2.4 Power / Power Supply
Power supply connector is a 2-position screw plug type (for 2-2.5 2
m
m
wire) used for
connecting the modem to a DC power supply. Polarity is irrelevant. Maximum
consumption is 3VA. Table of possible voltage options are shown below.
Option Nominal
Voltage
(V)
Voltage
Range (V)
DC/DC converter
on board
IDM50B - 12 12 9-18V SCW03A-05
IDM50B - 24 24 18-36V SCW03B-05
IDM50B - 48 48 36-72V SCW03C-05
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 5

3. HARDWARE CONFIGURATION
Hardware configuration is performed directly on the modem board by positioning the jumpers
according to the figure and the table below:
Figure 5. Jumper placement on the modem board
3.1 Jumpers placement (bold fase denotes factory default placement)
Feature Jumpers Option (ref. to AT&Mx command) Jumpers Placement
4-wire JP400, JP403 2-3
2/4-wire analog
line
JP400,
JP403
2-wire (only in FSK/MUX1 or
FSK/MUX2 mode)
JP400, JP403 1-2
JP405, JP406 1-2
4-wire (FSK
and V.29 mode)
Z input 600Ω,
Z output 600ΩJP401, JP402 2-3
JP405 1-2
4-wire (FSK/
MUX1 mode)
Z input 10kΩ
Z output 600ΩJP401, JP402, JP406 2-3
JP402 1-2Z input 600Ω,
Z output 10kΩJP401, JP405, JP406 2-3
4-wire (FSK/
MUX2 mode) Z input 10kΩ,
Z output 10kΩ
JP401, JP402, JP405,
JP406
2-3
JP405 1-2
2-wire (FSK/
MUX1 mode)
Z = 600Ω
JP401, JP402, JP406 2-3
Input & Output
Impedance
JP401,
JP402,
JP405,
JP406
2-wire (FSK/
MUX2 mode)
Z = 10kΩJP401, JP402, JP405,
JP406
2-3
Transmitter 3-state control off 1-2
Transmitter
3-state control
JP404
Transmitter 3-state control on
JP404
2-3
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 6

Feature Jumpers Option Jumpers Placement
JP407 ON
Proceed alternate radio relay signals
ALT1 and ALT2 to connector JP409 ON
JP407 OFF
Alternate radio
relay signal
presence on
connector
JP407,
JP409
Do not proceed alternate radio relay
signals ALT1 and ALT2 to connector JP409 OFF
JP411 ON
Proceed fail relay signals DEF1 and
DEF2 to connector JP412 ON
JP411 OFF
Fail relay signal
presence on
connector
JP411,
JP412
Do not proceed fail relay signals DEF1
and DEF2 to connector JP412 OFF
JP408 ON
Proceed the alternate squelch data
signals SQ+ and SQ- to connector JP410 ON
JP408 OFF
Squelch data signal
presence on
connector
JP408,
JP410
Do not proceed squelch data signals
SQ+ and SQ- to connector JP410 OFF
Enabled by switch on adapter cable 1-2
Bootstrap loader
operation
JP300
Enabled
JP300
2-3
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 7

4. SOFTWARE CONFIGURATION
4.1 Introduction to AT Commands
A command line is a string of characters sent from a DTE to the modem (DCE) while the
modem is in command mode. A command line has a prefix, a body, and a terminator. Each
command line must begin with the AT character sequence and must be terminated by a carriage
return. Commands entered in upper or lower case are accepted, but no combination is allowed.
Characters that precede the AT prefix are ignored.
The AT command body contains printable ASCII characters (32-126). The terminator is ASCII
<CR> character. The command line interpretation begins upon receipt of the carriage return
character. Empty AT command containing no characters but AT and <CR> is used as an
indication that modem is in command state and works correctly. Modem answers with
<CR><LF>OK<CR><LF>. <CR> and <LF> are control characters that precede and follow
every modem response message, so they will be omitted in following text.
The modem recognizes a backspace character (ASCII 08) after AT sequence. It clears
previously typed character from modem command buffer, allowing correction of wrong entered
command with no consequence.
If syntax error, invalid range or nonexistent command is detected in entered command line,
modem responds with “ERROR” message. Entered command is accepted only if previous AT
command is executed and acknowledged with corresponding message.
Advice: Since modem doesn’t support character echoing in command mode, it is
advised to activate local echo in terminal application (Telix, HyperTerminal,
etc.) used for AT setting. Local echo will help to insure which characters were
typed and sent to modem.
4.2 Entering Command Mode
By default, modem is in data mode. In data mode modem performs its basic function
transmitting data over preset channels. While modem is in data mode it is not allowed to
perform any setting procedures. To enter command mode perform following procedure:
1. Connect the communication cable to DIAG RS-232 connector at the modem front
panel. Data transmission and configuration are performed over the different ports. The
configuration adapter is used for firmware boot loading only.
2. a) If modem is turned off, push the SET button, turn on the modem by connecting its
power supply and keep the SET button pushed approximately for 1 second.
b) If modem is already turned on, push the SET button, then push and release the
RESET button while keeping the SET button pushed approximately for 1 second.
3. Modem will respond with its introductory message “IDM 50B LS vx.x” indicating
command mode and firmware version.
Important: For proper modem configuration 8N1data format at 1200b/s needs to be
selected in terminal application.
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4.3 Commands Description
Operational Mode
AT&Mx Sets FSK or CCITT V.29 operational modes. Valid values for x are:
x = 0 FSK mode where Zin/out=600Ω
x = 1 FSK/MUX1 mode where Zin=10k and Zout=600Ω
x = 2 FSK/MUX2 mode where Zin=600Ω/10k and Zout=10k
x = 3 V.29 mode, 4800bps
x = 4 V.29 mode, 7200bps
x = 5 V.29 mode, 9600bps
Example: AT&M5 command line sets 9600bps V.29 mode. Modem responds
with “OK” message.
Transmit Channel in FSK mode
AT&TC23/y Sets CCITT V.23/1 and V.23/2 channels for data transmission. Valid
range for y is 0, 1 and 2 corresponding to V.23/0 and V.23/1 at 600Bd,
and V.23/2 at 1200Bd channels, respectively.
AT&TC701 Sets Cegelec 1200Bd 701 channel for data transmission.
AT&TC60x Sets Cegelec 600Bd 60x channels for data transmission. Valid range
for x is 1-3, corresponding to channels 601 to 603.
AT&TC40x/y Sets CCITT R.38A 200/300Bd channels for data transmission. Valid
range for x is 1-7, corresponding to channels 401 to 407; valid range
for y is 1, 2 corresponding to 200, 300Bd channels baud rate,
respectively.
AT&TC30x Sets CCITT R.38B 200Bd channels for data transmission. Valid range
for x is 1-8, corresponding to channels 301 to 308.
AT&TC2xx Sets CCITT R.37 100Bd channels for data transmission. Valid range
for xx is 01-12, corresponding to channels 201 to 212.
AT&TC1xx Sets CCITT R.35 50Bd channels for data transmission. Valid range for
xx is 01-24, corresponding to channels 101 to 124.
Example: AT&TC402/2 command line sets channel 402 at 300Bd data rate for
data transmission. Modem responds with “OK” message.
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 9

Receive Channel in FSK mode
AT&RC23/y Sets CCITT V.23/1 and V.23/2 channels for data reception. Valid
range for y is 1, 2 corresponding to V23/0 and V.23/1 at 600Bd, and
V.23/2 at 1200Bd channels, respectively.
AT&RC701 Sets Cegelec 1200Bd 701 channel for data reception.
AT&RC60x Sets Cegelec 600Bd 60x channels for data reception. Valid range for x
is 1-3, corresponding to channels 601 to 603.
AT&RC40x/y Sets CCITT R.38A 200/300Bd channels for data reception. Valid range
for x is 1-6, corresponding to channels 401 to 407; valid range for y is
1, 2 corresponding to 200, 300Bd channels baud rate, respectively.
AT&RC30x Sets CCITT R.38B 200Bd channels for data reception. Valid range for
x is 1-8, corresponding to channels 301 to 308.
AT&RC2xx Sets CCITT R.37 100Bd channels for data transmission. Valid range
for xx is 01-12, corresponding to channels 201 to 212.
AT&RC1xx Sets CCITT R.35 50Bd channels for data transmission. Valid range for
xx is 01-24, corresponding to channels 101 to 124.
Example: AT&RC123 command line sets channel 123 at 50Bd data rate for data
reception. Modem responds with “OK” message.
Reverse FSK frequencies
AT&RFx Sets frequencies order in FSK modes. When set to "0" then normal
FSK frequencies order are set and -F corresponds to data line SPACE
condition and +F corresponds to data line MARK condition. When set
to "1" then reverse FSK frequencies order are set and -F corresponds to
data line MARK condition and +F corresponds to data line SPACE
condition. If invalid range is entered, modem responds with “ERROR”
message, otherwise responds with “OK” message.
Example: AT&RF0 command line sets normal FSK frequencies order. Modem
responds with “OK” message.
Transmit Level
AT&TLxx Sets transmission level in dBm units in 1dB steps. Valid range for FSK
is 0 to 32, corresponding to 0dBm to -32dBm, except in FSK/MUX2
mode where range is 06 to 32, corresponding to -6dBm to -32dBm. If
invalid range is entered, modem responds with “ERROR” message,
otherwise responds with “OK” message.
Notice: Transmit level is referred to loaded output.
Example: AT&TL8 command line sets –8dBm transmit level. Modem responds
with “OK” message.
Receive Level
AT&RLxx Sets receive level in dBm units in FSK mode. In V.29 mode receive
level is fixed to R = -26dBm and this settings is ignored. For FSK
mode received level R is adjustable by step of 1dB in range from 0 to
–36 dBm. Signal is detected at R – 9 dB or grater; signal loss is
detected at R - 12 dB or lower. Detection limit is at R – 12 dB (loss of
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009 10