Westermo MA-43 User manual

Addressable modem
INSTALLATION MANUAL
6043-2202
MA-43
MA-43 H
©Westermo Teleindustri AB • 001 • REV. A
Galvanic
Isolation
Transient
Protection
Balanced
Transmission
CE
Approved
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36043-2202
Specifications
Transmission Asynchronous, full/half duplex or simplex
Interface 1 EIA RS- 3 -C/ITU-T V. 4, 5-position D-sub, female
Interface 2 EIA RS-4 -A/RS-485/V.11, 5-position screw block
Transmission rates Up to 38.4 kbit/s
Indicators Power, RD, TD, DCD, CTS, RTS
Humidity 0–95% RH, non-condensing
Overvoltage protection Mains: Breakdown voltage 440V at 30V AC
and 0V at 115V AC
Interface 2: Breakdown voltage
transmitter and receiver 7V
Surge capacity 0.6 kW for 1 ms
Transient protection
Po er/Line Yes/Yes
Isolation Galvanic isolation with opto-coupler
(data transmission) and transformer (supply)
Isolation RMS
Data interface 1 500 V
Po er supply 3 000 V
Po er supply Switchable 115/ 30V +15/–10%
Frequency 48–6 Hz
Fuse 100 mA F 5x 0 mm Littlefuse
Po er consumption 48 mA / 4 mA
Temperature range 5–50°C, ambient temperature
Dimensions 161x139x53 mm (WxHxD)
Weight 0.5 kg
Mounting Table top.
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46043-2202
Master
Start character (hex)
S itch settings MA-43
S1 Selection of power supply 115/ 30V AC
S , S3 Selection of addresses
S4 Selection of operation
S5 Selection of communication parameters
S6 Selection of - or 4-wire communication
and termination
ON
1 345678
ON
1 3456
ON
1 34
S4
ON
1 34
S4 04 (EOT)
ON
1 34
S4 1B (ESC)
Master
Number of start charter
ON
1 34
S4 4
ON
1 34
S4 1
Master
Timed address frame
ON
1 34
S4 Yes
ON
1 34
S4 No
Master
Reserved
ON
1 34
S4 Not in use
ON
1 34
S4 Not in use
Slave
Buffered
ON
1 34
S4 Yes
ON
1 34
S4 No
Slave
Reserved
ON
1 34
S4 Not in use
ON
1 34
S4 Not in use
S5 S6
S2
S3
S1
F1 S6
S5
S4
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56043-2202
Bit/s
ON
1 345678
S5 300
Bits per character
ON
1 345678
S5 8
ON
1 345678
S5 7
Stop bits
ON
1 345678
S5
ON
1 345678
S5 1
Termination
ith fail-safe
S6 -wire
S6 4-wire
S6 No
termination
Flo control
ON
1 345678
S5 Xon/Xoff
ON
1 345678
S5 RTS/CTS
Selection of 2- or 4- ire
S6 -wire
S6 4-wire
Factory settings
ON
1 345678
S5
Parity
ON
1 345678
S5 Odd
ON
1 345678
S5 No
ON
1 345678
S5 Even
ON
1 345678
S5 No
ON
1 345678
S5 600
ON
1 345678
S5 1 00
ON
1 345678
S5 400
ON
1 345678
S5 4800
ON
1 345678
S5 9600
ON
1 345678
S5 19 00
ON
1 345678
S5 38400
ON
1 34
S4
ON
1 3456
ON
1 3456
S6
ON
1 3456
ON
1 3456
ON
1 3456
ON
1 3456
The MA-43 system has to be terminated and
have a fail-safe function. Fail-safe forces a three
stated line to be in the off state.
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66043-2202
General
MA-43 is an addressable short haul modem which can be used in a master/slave system
with unintelligent slaves. Unintelligent slaves are devices which cannot recognize any type
of addressing.
MA-43 is a flexible product designed to be integrated into many different and complex
systems. Any data from single ASCII characters to large binary data files can be transferred
through the MA-43. The protocol is flexible so it can fit into many systems. For this reason
the addressing protocol is selectable so that data cannot appear as an address to a slave. If
just simple character data is going to be exchanged then a simple protocol can be used to
save time and complexity. However, if binary data files are going to be transmitted then
the contents of the data could be anything. In this case a more complex addressing system
has to be used- timed mode. In this mode there has to be a period of no data before and
after the addressing, which is a condition that will not occur in binary data file transfer.
Each MA-43 in a network can have different baud rate, parity, stop bits and flow con-
trol. This makes it possible to connect different equipment with different flow control
and speed to the same bus.
Protocol
The protocol is an address frame followed by data for the addressed unit. There is no
limit for the number of data bytes that can be sent to and from an addressed slave after
the address frame. The address frame is made of two parts, a start sequence and an
address. The start sequence consists of one or four equal start characters (EOT or ESC)
and the address which is just a single character corresponding to the slave address. The
address frame is followed by an unlimited number of data characters to the addressed
unit. However, the datastream should not include data equal to the start sequence, if this
happens a new unit is addressed and the rest of the data is sent to a different unit.
The protocol is set in the master MA-43 so all slaves are independent of the chosen
protocol.
When a slave receives an address it is compared with its own strapped address. If the
address matches all following data received on the bus will be transfered to the RS- 3
side. This will be done until another address is received. The addressed slave is the only
slave that can transmit data on the bus. When a new address is received the slave will
stop the transmitting immediately even if there is still data in the buffer. The bus is fully
controlled by the MA-43 so no status signals are required from the terminal equipment.
Address frame
Data DataStart sequence Address
Time Address frame Time
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76043-2202
Untimed address frame
The master MA-43 searches for the start sequence and address in the RS- 3 data stre-
am. When a valid start sequence is detected the next received character is transmitted
as an address to all connected slaves. If there is more than one character in the start
sequence, there is a time limit between two subsequent start characters. The time bet-
ween two start characters has to be less than 10 byte times. When a start sequence is
detected the next character is an address. There is no time-limit between the last start
character and the address character.
If another character is received instead of a start character, this character and any
previously accepted start characters for this address frame search, is transmitted and the
MA-43 looks for a new start character.
If the time expire between characters in an address frame, the previously accepted
characters for this address frame search are transmitted and the MA-43 looks for a new
start character.
UNTIMED ADDRESS
1 Start character
4 Start characters
T1 has to be less than 10 byte times
There is no time-limits when only 1 start character is used.
Data
Data Data
Data Data
Start
Start
T1 Start T1 Start StartT1
Address
Address
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86043-2202
Timed address frame
This mode uses the same protocol as untimed however in this mode MA-43 requires a
quiet period before and after the address frame. A quiet period is a time-period when
no character of any kind is sent on the masters RS- 3 TD signal. The quiet periods has
to be at least 10 byte times.
After 10 byte times quiet since the last character on the RS- 3 TD line the MA-43
master waits for a start character. There is also in this mode a time-limit between cha-
racters in the startframe. The time-limit between characters is also 10 byte times. In this
timed mode the time-limit also concerns the gap between the last start character and
the address character. When the address character is received MA-43 requires 10 byte
times quiet before the address frame is accepted and the new address can be transmitt-
ted to all connected slaves.
If another character is received instead of a start character, this character and any
previously accepted start characters for this address frame search are transmitted and
10 new byte times have to pass before the MA-43 looks for a new start character.
If the time expires between characters in an address frame, the previously accepted
characters for this address frame search are transmitted and the MA-43 looks for a new
start character.
Buffered/Unbuffered
The slaves can be strapped to work with or without buffers. The buffer in the slaves is
4 kbytes. When the slave is working as buffered all data is buffered, even if the slave is
not addressed. So if no flow control is used the buffer will overflow and starts to overw-
rite itself. When unbuffered the slaves only accept data on the RS- 3 side as long as
they are addressed.
TIMED ADDRESS
1 Start character
4 Start characters
T1 has to be less than 10 byte times. T2 has to be more than 10 byte times.
Data
Data DataStart T1 Start T1 Start T1T2
Data T2 T2T1Start Address Data
Start T1 Address T2
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96043-2202
Flo control
The RS- 3 flow control can be done in two different ways, software XON/XOFF or
hardware RTS/CTS. This is individually selectable for each connected unit.
The system itself has flow control internally on the RS4 /485 bus. The internal flow
control is used to transfer the hardware control signals across the network and indicates
that the buffer is full.
A MA-43 system can have different baudrates for different connected equipment.
Because of this there can be flow control signalling introduced by the MA-43 units. This
means for example, that if an XON/XOFF protocol is used the XOFF signal can be sent
by either the addressed user equipment or one of the two MA-43s which are involved in
the talking, if a buffer is filled up.
RTS/CTS
The CTS signal is used to control the data stream from a user to a MA-43. CTS is high
when the MA-43 is ready to receive characters.
The RTS signal is used to control the data stream from a MA-43 to the user. When the
user equipment is ready to receive characters RTS has to be high.
LED Indicators
MA-43 has 7 LED indicators. The LEDs has the following function.
POWER: Fixed light indicates normal function. If it is flashing the unit is faulty
(watchdog).
RD: Indicates RS- 3 receiving data. Light off when no data received.
DCD: Lights when this slave is addressed, flashing when master is in test mode.
RTS: Lights when connected unit has RTS in active state.
CTS: Lights when MA-43 is ready to receive data.
TD: Indicates RS- 3 transmitting data. Light off when no data transmitted.
RXBUS: Lights when data is received from the bus. This LED is only visible
when the box is open.
2-Wire system
When a slave has anything to send this will be sent as soon as the slave is addressed.
The MA-43 can not follow application protocols, so it is possible to get data collision on
the -wire bus if the user protocol is not disciplined. i.e the equipment cannot answer
polls or commands before the whole message is received from the talking partner.
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10 6043-2202
Test
Test commands can be sent from a standard terminal with an RS- 3 connection. The
terminal is connected to the master MA-43 (address 00), which is the only MA-43 that
can act on the test commands. To be able to give test commands the MA-43 has to be
in the test mode. Test mode can only be entered directly after power up or reset of the
master MA-43. To enter the test mode, send an ASCII 0 as the first character to the
master MA-43 after power up or reset. The MA-43 then answers with a character string
(***** MA-43 TEST MODE ******). During the test phase normal data traffic will be
disturbed. The MA-43 will leave testmode with a reset as soon as a start character is
sent to the master MA-43.
The following test is available:TEST1.
Test 1
The test is designed to be used to control an installation. TEST1 first resets all slaves,
then all slave addresses are polled. The slaves which recognises their own address ans-
wer with a configuration message. 10 slaves will be displayed in ascending order, the user
is asked to press a key to continue to see 10 new slaves, only the answering slaves will
be displayed. The units will answer with the information seen below. To test the RS- 3
hardware the slaves have to be looped back between TD and RD (position and 3 in
the 5-pole D-sub). The test can run without TD and RD looped on the slaves, but the
RS- 3 interface will not be tested.
Example
Address Baudrate Flo control Buffered Looped
01 9600,e,8,1 RTS/CTS Buffered OK
03 4800,n,7,1 XON/XOFF No OK
0A 4800,n,7,1 XON/XOFF No No loop
Addresses and commands
All commands and addresses are only accepted through the master MA-43.
Decimal Hex Address/Command
0 00 Master unit.
1– 39 01 – EF Slave units.
40 F0 Broadcast.
41– 53 F1 – FD Reserved.
54 FE Reset, resets the whole MA-43 system.
55 FF Reserved.
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116043-2202
Termination
The MA-43 system has to be terminated and have a fail safe. The last units on the bus
should have termination switched on. The failsafe circuit ensures that when all transmitt-
ters are tristated the line can not float and so cause possible false data readings.
Address assignment
S and S3 is two hexadecimal switches which together determine the unit address. The
usable addresses are 0 to 39 (hexadecimal 00 to EF). The addresses 40 to 55 (F0 to
FF) are used for commands and cannot be used as slave addresses. S3 is the high part of
the hexadecimal address and S is the low part. If S3 is in position A and S in position 1
the unit will become the address A1. Adress 00 will become master. Only one master is
allowed per system.
Direction Connection CCITT V.11
no. Description
Receiver 1 A’ (R+)
Receiver B’ (R-)
Transmitter 3 A (T+)
Transmitter 4 B (T-)
5 Shield
Connections
Line connection
(5-Position screw-terminal)
Direction Connection CCITT V.24 Signal name
Code
I2 103 TD/Transmitted data
O3 104 RD/Received Data
I4 105 RTS/Request To Send
O5 106 CTS/Clear To Send
O6 107 DSR/Data Set Ready
– 7 102 SG/Signal Ground
I = Input O = Output on MA-43
Terminal connection (DCE)
(RS- 3 -C/V. 4, 5-Position D-sub, female)
The definitions R+/R–, T+/T– can be various between
different manufactures.
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12 6043-2202
Max 1 00 metre/Max 3 connections
=Termination
Max 0.3 metre
Max 0.3 metre
=Termination
A
B
ABABAB
A’
B’
A
B
B’ A’ A’BBAB’A’BAAB’
MA-43 Master
MA-43 Slave
MA-43 SlaveMA-43 Slave
MA-43 Slave
MA-43 SlaveMA-43 Slave
MA-43 Master
N.B. R+/R–, T+/T– definitations are not standard, it can help to shift A and B
if the unit does not work.
Transmission range (interface 2)
Use twisted pair cable. Max transmission range 1 00 metres.
(cable specifications 0.3 mm and capacitance 4 pF/m).
The transmission range will increase if a cable with lower capacitance and larger
diameter is used.
Use shielded cable in heavy industrial environments.
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136043-2202
S itch settings MA-43H
Master
Start character
ON
1 34
S4 04 (EOT)
ON
1 34
S4 1B (ESC)
Master
Echo
ON
1 34
S4 No echo
ON
1 34
S4 Echo
Master
Mode
ON
1 34
S4 Hayes
ON
1 34
S4 S4:1
Master
Result codes
ON
1 34
S4 No codes
ON
1 34
S4 Result codes
Slave
Buffered
ON
1 34
S4 Yes
ON
1 34
S4 No
Slave
Mode
ON
1 34
S4 Hayes
ON
1 34
S4 Normal
Factory settings
ON
1 34
S4 Master
ON
1 34
S4 Slave
Slave S4: 1 and 4 is not used
In the MA-43H the timed address mode has been replaced with a Hayes mode.
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14 6043-2202
Connect MA-43 H
ATDnnn<CR> n is number from 1 to 1 6 followed by a CR.
Example:
To connect to hex address 30, ATD48<CR>.
To connect to hex address , ATD <CR>.
The modem will reply with CONNECT or NO ANSWER.
Disconnect MA-43 H
To disconnect, just send +++ and ATH0 or ATH. There has to be a quiet period of
10 byte times before the +++.
10 byte times with 9 600 baud is approximately 10 ms (The time is at least 100/baud-
rate). The time between the +signs has to be less than 300 ms. If any other command
will be sent after +++ the modem disconnects and answer with ERROR.
The modem will then be ready for a new address.
Disconnect sequence:
<quiet>
+++
OK
ATH0<CR>
NO CARRIER
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6043-2202 01.01 Mälartryck AB, Eskilstuna, Sweden
Westermo Teleindustri AB • S-640 40 Stora Sundby, Sweden
Phone [phone] Fax [phone]
E-mail: [email protected] • Westermo Web site: www.westermo.se
Westermo Teleindustri AB have distributors in several countries,
contact us for further information.
Westermo Data Communications GmbH
Bruchsaler Straße 18, 68753 Waghäusel
Tel.: [phone] • Fax.:[phone]
E-Mail: [email protected] • Web: www.westermo.de
Westermo Data Communications Ltd
Unit 14 Talisman Business Centre • Duncan Road
Park Gate, Southampton • SO31 7GA
Phone: [phone] • Fax.:[phone]
E-Mail: [email protected] • Web: www.westermo.co.uk
Subsidiaries
Block diagram
ADDRESS
FUNCTION
PROCESSOR
BUFFER
UART
+5V
0V
SG
DSR
CTS
RTS
RD
TD
T+
T-
R+
R-
3
4
1
2
2
3
4
5
6
7
V24/ RS-232
V.11/ RS-422
RS-485
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