Sponsored Article

AutoLog UHF / VHF Radio modems

21 October 2009

AutoLog WSN Radio modem series has been designed to meet high specifications.

AutoLog® WSN Radio Modem Series Multi Repeating
AutoLog® WSN Radio Modem Series Multi Repeating

It offers very cost effective radio modems for stand alone applications or for integration into OEM products. Supports, for example, routing for Modbus/IEC870 protocol. Cost effective pricing!

The design has been optimised for reliability and low current consumption, making the WSN suitable for operation on remote sites without mains power. Applications include security, command & control, data logging, SCADA, telemetry, remote switching or any similar applications where serial data needs to be transmitted and a cable is not the most practical solution. The WSN is available with two different transmit powers.

Serial Operation
The WSN requires no knowledge of the data it is transmitting; data can simply be sent and received with minimal delay. Transmission control can either use RTS control signals or be configured for automatic initiation of transmission on receipt of serial data. In either case, the radio provides a CTS output which can optionally be used for flow control. The WSN incorporates an internal buffer to cope with situations where the interface data rate differs from the over-air rate.

Internal Soft Modem
The WSN features an internal “soft modem” which offers unparalleled performance and flexibility over a wide range of speeds and formats and enables future formats to be handled by software upgrade. Within a 12.5kHz channel, the over-air transmission from the unit can be user programmed for a range of speeds. If the maximum speed is not required, the unit can be configured for a lower speed to give an improved receiver threshold.

For 150, 300, 600,1200 & 2400 baud, FSK/FFSK is used with both Bell202 and V.23 supported. At 4800bps GMSK modulation is used, while at 9600bps, the modulation is 4-level FSK.

Channel Selection
The WSN can be programmed for simplex or semiduplex operation with up to 80 discrete channels. Alternatively, complete band allocations like the UK MPT1329 and MPT1411 bands can be loaded. Once programmed, the channels can then be selected via rotary switches on the front panel.

RF Power
The transmit power can be accurately set using a locally connected PC with the supplied software. There are two transmit power ranges available. The low power WSN450 & WSN869 versions can be set between 10mW and 750mW, while the higher power WSN170, WSN470 & WSN870 versions can be set between 50mW and 5W.

The parameters of the WSN can be configured through the local serial port using DOS or Windows 95/98/2000/XP based software. The individual configurations can be stored on disc for future use or printed.

Status LEDs
The WSN has five LEDs to enable the operator to see at a glance the status of the radio and its interfaces. The System LED provides the operator with a quick visual health check and if the software detects an error, a code is flashed on the LED to indicate the error.

Squelch Tail Elimination
For old or non tolerant protocols, where the presence of a mute (squelch) tail may cause a problem at the end of a message, a simple packetisation option can be enabled using the configuration software.

Forward error correction
Forward error correction is a programmable option at 9600bps, but as with all FECs, the associated overhead will reduce the effective data throughput rate when it is selected. Error correction offers insignificant performance improvements below 9600bps so the option is permanently disabled at those lower rates.

“RSSI” Receives Signal Strength Indication
The RSSI signal is accurately measured by an internal A-D converter and compared to an individually calibrated RSSI graph within the processor. The signal strength can then be accurately read in engineering units from a PC connected to the serial port.

Power Save Mode
The WSN has both internal and external power save modes.

Internal Power Save Mode
The microprocessor controls the on/off function of the receiver and after a pre-programmed time the MPU will switch on the receiver to look for a carrier. If a carrier is not detected then the transceiver goes back into sleep mode. If during the time the transceiver is awake a carrier is received, the unit will stay awake. After the carrier drops out, the receiver will stay awake until the programmed resume time elapses. Once the resume time has elapsed the transceiver will go back into sleep mode. The power-save, wake and resume times are all user programmable.

External Power Save Mode
In the external mode the ON/OFF function of the modem is controlled by the host via the DTR line.

Operation Modes
Transparent Operation

The WSN can operate transparently without packetising the data and without adding any other overheads, thereby maximising data throughput rates. It requires no knowledge of the data it is transmitting. Data is simply transmitted and received with minimal delay.

Protocol specific modem
The radio recognises a complete frame and only transmits and receives data conforming to that format. No addressing of radios or routing of data is performed. Protocols such as MODBUS & DNP3 can be supported in this way.

Routing modem
The radios recognise a protocol specific frame and the address to which the frame is to be sent. Routing information must be stored in each radio for each destination address that requires the use of repeaters. Any radio in the system can operate as a repeater. The radio does not perform any acknowledgement or retries. Any protocol using a fixed address field such as MODBUS can be supported.

PC Software
Dedicated PC software running under DOS or Windows 95/98/2000/XP allows configuration of the radios. This software provides unrivalled versatility combined with ease of use for the operator.

FF-Automation & coming activities!
FF-Automation is at MENDT exhibition
(5th Middle East Nondestructive Testing Conference & Exhibition 2009). Exhibition takes place in Bahrain Gulf Hotel November 8-11,2009)

Contact Details and Archive...

Print this page | E-mail this page