FAQs

RS-422 uses 2 wires for simplex transmission. RS-485 can use 2 wires for half duplex transmission. Full duplex systems are implemented using 4 wires. Both RS422 and RS485 can be used in multidrop configurations however precautions must be taken to prevent more than one transmitter being active on the same bus at once.

Not on the line side because the MA-12 and MA-21 have different interfaces. The MA-12 use Westermo’s own interface, a 10 mA balanced current loop. While the MA-21 use a 20 mA current loop. The two are not compatible

The switch settings could be wrong in the MA-42 or the control signals between PC and converter could be missing. RS-485 which is a 2-wire system, uses the same cable pair for transmitting and receiving data. The converter must have a physical control signal from the RS-232 interface to know whether it should receive or transmit data. Usually the handshake signals RTS or DTR are used to switch transmitting direction. To make this work the cable between the converter and PC must contain connections for the handshake signals and the program in the PC must be able to handle this kind of handshaking. Also the switch settings in the MA-42 must be changed from always active to transmitter activated by RTS or transmitter activated by DTR.

A common problem with some equipment is that the polarity of the line is opposite to Westermo’s interfaces. This depends on how one defines polarity-at rest or when there are some communication on the line. If the line has incorrect polarity one can usually see this on the RA-48 LED’s or the connected units, these light up when they ought to be off and vice versa. If the system has not been changed other than the connection of the RA-48, try changing the polarity off the connections, that is the wire connected on pin 3 changes place with pin 4 and the wire on pin 1 changes place with the wire connected to pin 2 on the screw terminals on both sides of the RA-48.

The FD-10 is just transferring the I/O information and not the profibus frame. The I/O information will be inserted in a profibus DP frame on the remote side. The FD-10 is a profibus slave and need a profibus master to control the communication in the profibus network.

RS-422 uses 2 wires for simplex transmission. RS-485 can use 2 wires for half duplex transmission. Full duplex systems are implemented using 4 wires. Both RS422 and RS485 can be used in multidrop configurations however precautions must be taken to prevent more than one transmitter being active on the same bus at once.

Data-control: The data flow starts on the first bit. RTS-control: The data flow is controlled by handshaking. RTS (request to send) and CTS (Clear to send).

The SIM card is in the modem and the PIN code is disabled. S0 are set for something different than 0 and the modem seems to be answering, but it's only silence and nothing happens. A2 The number you are calling to the GSM modem is the normal voice number. When you want to use the GSM-modem for data communication you must have a special data number to the SIM card otherwise will not the GSM-modem understand that there is a data call coming in. To check if this is correct could be tested with the AT+CRC=1. The modem will then report the type of connection you get when there is a call coming in. It's sometimes possible to make a work around with the use of the AT+CSNS=4. With this command the modem will answer in data mode regardless of number that has been used. This is a feature that some operators have blocked. A special data number could be obtained from your operator.

The ‘LocalIP’ is equal to the IP address of the ED-10 unit and ‘RemoteIP’ is used slightly different in the UDP and TCP versions. UDP: ‘RemoteIP’ is the address of the unit that the ED-10 UDP will reply to and if ‘RemoteIP’ is set to 255.255.255.255, then the unit will reply with broadcast messages. TCP: ‘RemoteIP’ is the address of the unit that will be allowed to establish a session with the ED-10 TCP. If ‘RemoteIP’ is set to 255.255.255.255, then the unit will allow any unit to establish a session.

Port numbers is used to separate the type of data since the same IP address is used for communication. E.g. Mail client application – port 25(smtp) – Mail server application Browser application – port 80(www) – Web server

If all your units are in the same LAN the ‘Gateway IP’ can be set to 0.0.0.0. But if the ED-10 TCP shall communicate to a PC in another LAN, then shall the ‘Gateway IP’ in the ED-10 TCP shall be set to the address of the Router that is the links to the network where the PC is connected.

This question has three answers.

1. To use all functions in the ED-20 a special cable is required and that specific cable is included in the product combination (3902-0240). This combination contains 1pc ED-20 (3609-3001), 1pc TD-35 LV (3613-0001), 1pc Cable (1211-2168).
2. A serial crossover cable with 2-3, 3-2, 5-5, 7-8 and 8-7 can be used but not in combination with the setting DCD Control=ON.
3. A simple serial crossover cable with only 2-3, 3-2 and 5-5 can be used but not in combination with the setting DCD Control=ON nor the Serial Interface Flow Control = RTS/CTS. The cable can also be ordered separately, Art.no. 1211-2168 or a drawing can be downloaded.