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EZL- 300W - WiFi converter - RS-232
NOTE: Product end of life

EZL-300W is a robused encased RS232 converter for wireless data transmission via 802.11b with a Real-Time Operating System. The WiFi card containing radio part is inserted into the box. Module can be without further programming connected directly to RS-232 interface of any device.


Converter EZL-300W converts the serial line RS-232C to wireless Ethernet - standard WiFi 802.11b for hundreds of meters. Communication can be realized either between the device and Acces Point (AP) or two devices together(AD HOC mode). Radio part is realized by the WiFi PCMCIA card inserted into the device.
The result is a converter of wireless Ethernet which differs from classic RS-232 / Ethernet converter only in the fact, that instead of RJ45 connector for cable Ethernet connection is used internal or external aerial.

Aerial conception: At request we can supply an additional PCMCIA card for the device with a reverse MMCX connector for connection of a external aerial (optional component).


Differences from the version EZL-300W Lite:

  • EZL 300W Lite is cheaper than EZL 300W
  • EZL 300W Lite does not support "Remote Management Function via telnet" (configuration over the network in the terminal). That means that it can be configured only by a terminal on the serial port (ezSerialConfig) or by a special configuration utility over the network. (ezConfig)..
  • EZL 300W supports the EAP-MD5 authentification and the Lite version does not support the MD5 coding at all. Version EZL 300W Lite cannot be used within those wireless networks which require MD5 coding..

EZL - 90 module

EZL - 300W module



  • Ethernet Network ( WiFi IEEE 802.11b ) - slot for WiFi 3.3V PCMCIA card 
  • 1x full serial port RS-232 accessible via WiFi Ethernet
  • Virtual serial port (ezVSP) for Windows - e.g. as COM 7 in PC  
  • Devices together can wirelessly interconnect RS-232 port over WiFi.
  • MIC Real-Time Operating System for complete configuration, control and upgrade of the module by any RS-232 terminal (suitable also for other PC OS than Windows - e.g. Linux, UNIX)
  • Intuitive and simple cofiguration software for Windows (by the means of  WiFi, RS-232, AT commands), very easy installation
  • Independent configuration of the module's parameters on PC's OS via MIC Real-Time OS and TELNET
  • Data safety - support of all possible security precautions for WiFi technology - SSID, WEP 64bit/128bit coding, selection of communication channel, password-protected access into settings
  • Authentication protocol EAP-MD5 - allows prevention of illegal access into the WiFi network
  • LED indication of the operation and communication
  • Powered by an external DC 5V power supply unit. A stabilizer is a component of the module.
  • Robust construction.

Datasheets & Links


EZL-300W Lite datasheet (1 page)
EZL-300W datasheet
Detailed manual for EZL-300W Lite (37 pages)
EZL-300W manual



EZL-300W converter connected to the device communicating via serial RS-232 transmission. Opposite side is represented by other WiFi device (in so called Ad-hoc mode) or WiFi AP (Access Point), which accesses serial port into classic Ethernet network. In case of using more WiFi Access Points connected into single network the converter can move freely between them.

  • Remote sensors' comunication (e.g. electronical thermometers) and PC.
  • Wireless data transmission for projection of information on displays.
  • Immediate data retrieving of the MaR system (Measuring and Regulation) by a notebook or PDA attendance.
  • Wireless realization of factory networks with connection to LAN and Internet.
  • Security systems
  • Remote controlling of mobile machines
  • Data synchronization of portable devices with PC
  • Wireless communication of measuring devices (multimeters, oscilloscopes and others)


Serial port RS-232  
+ Data bits 7 or 8
+ Parity None / Odd / Even
+ Baud rates 1.2 .. 115.2 kBd - whole range (full duplex).
+ Data flow control CTS/RTS, None
+ Interface 9 pin Dsub - male (RxD,TxD,RTS,CTS,DSR,DTR,GND)
+ Used RS-232 signals RxD,TxD,RTS,CTS, DSR, DTR
- RTS and CTS pins are used after activation only
+ Buffer size 1 kbytes reception buffer and 512 bytes transmission buffer
Ethernet port  
+ Interface PCMCIA card slot (16bit, 3.3V)
(WiFi - Prism 2.5 compatible interface)
+ Compatibility WiFi - IEEE802.11b Wireless LAN (infrastructure/ad-hoc)
+ Supported protocols TCP, UDP, IP, ICMP, ARP, DHCP, WEP, TELNET, EAP-MD5
+ TCP connection closing Data - timeout (optional)
+ Security WEP 64/128bit (optional), SSID, channel number
+ Antenne Integrated or Integrated + Ext. MMCX connector
Environmental conditions  
+ Operating temperature 0– 70 °C
Physical parameters  
+ Voltage requirements 5V DC
- barrel (coaxial) power connector, GND on the shield
+ Dimensions 137x 78x 28[mm] (H x W x D )
+ Weight 310g
Functional parameters  
Device SETUP configuration possibilities  - over any RS-232 - ezSerialConfig Windows software
 - over any serial terminal - MIC OS (full setup), AT commands
 - over WiFi - ezConfig Windows software
 - firmware download over RS-232 (ISP mode) - wflash Windows software
LED diagnostic LINK & Activity on serial and WLAN
Operating System  MIC Real-Time OS for full module setup over RS-232 terminal


RS-232 interface:

Ethernet communication  modes :

Converter can behave as a client/server device according to chosen MUX TYPE (function modes):


Communication mode Protocol Connection Type  
T2S TCP Passive = TCP Server Converter listens on the selected port and awaits client's connection which can thereafter send or receive data
ATC TCP TCP Client or TCP Server Communication is operated by transmitting AT commands over serial line which allows setting of the client/server mode (COD, T2S).
COD TCP Active = TCP Client Converter establishes connection when RS-232 port receives the data and allows a transmission.
U2S UDP Point-to-Point Broadcast Defined TCP port awaits data and sends them to IP address without a transmission control. This allows using a broadcast.


Other supported communication protocols : ARP, EZCFG, DHCP, TELNET


Program ezVSP (Virtual Serial Port):

  • Instalation of this program is conditioned by ownership of at least one module.
  • During installation it's necessary to enter the MAC address of the module and a key which is obtained by a registration on Sollae webpage. Further installation description can be found in the program manual.


Configuration over ezSerialConfig:

  • To create contact between configuration program and the module the communication WiFi card must not be connected.
  • Configured baud rate of the module's serial port doesn't affect the communication speed at configuration (communication baud rate is 19200bps)..
  • Do not confuse the EzSerialConfig program for EZL-300W with the same program for EZL-300W Lite (EZL-80). They are two different programs.



  • The connection of the module's serial port and the application must be performed by so called "zero mode" principle. That means interconnection of the RxD - TxD and RTS - CTS pins from the view of both ends of the connecting cable.
  • Considering the module's internal supply voltage 3.3V (modul contains the stabilizer from 5V) it's necessary for reliable function to use a WiFi card for operation at the 3.3V level.


Ordering versions

The EZL-300 device can be supplied in several packages, according to the bellow described ordering number. If you do not specify a device version in your order, we will send you a preffered type. The delivery terms of the non-preffered types should be verified by phone or requested in your order confirmation.

OID Device types
600 135
End of life
EZL-300W starting set
- EZL-300W unit (photo) [600154]
- EU Power DC adaptor 5V [600 123]
- PCMCIA WLAN card without external antenne (photo) [600133]
- DB9 LapLink cable 2m (photo) [600063]
- CD
600 136
End of life
EZL-300W Lite starting set
- EZL-300W Lite unit (photo) [600155]
- EU Power DC adaptor 5V [600 123]
- PCMCIA WLAN card without external antenne (photo) [600133]
- DB9 LapLink cable 2m (photo) [600063]
- CD
600 156
End of life
EZL-300W Ext. Antenne starting set
- EZL-300W unit (photo) [600154]
- EU Power DC adaptor 5V [600 123]
- PCMCIA WLAN card with external MMCX antenne [600134]
- DB9 LapLink cable 2m (photo) [600063]
- CD
600 157
End of life
EZL-300W Lite Ext. Antenne starting set
- EZL-300W Lite unit (photo) [600155]
- EU Power DC adaptor 5V [600 123]
- PCMCIA WLAN card with external MMCX antenne [600134]
- DB9 LapLink cable 2m (photo) [600063]
- CD


Actual prices can be found in the pricelist.

Download software

  • ezConfig softwareezConfig - for module configuration from PC via LAN and WiFi. Allows setting parameters for Ethernet and serial transmision.
  • (85kB)
  • ezSerialConfig SoftwareezSerialConfig - for module configuration via serial RS-232 port
    Allows configuring all parameters (for WiFi, Ethernet, serial transmission).
  • (17kB)
  • wflash programwflash - for loading firmware via RS-232.
    The latest firmware can be freely downloaded from producer's webpage.
  • (69kB)
  • hotflash - for firmware loading via WiFi
  • (97kB)
  • ezTerm softwareezTerm - for testing communication (terminal for PC)
  • (69kB)
  • ez Virtual Serial Port softwareezVSP - Virtual Serial Port for Windows - creates on the PC a virtual serial port (e.g. COM 7) which can be referenced by other programs and communicated as with the RS-232 interface even though the data transfer is actually via TCP/IP.
    Note: Program is intended for Windows 2000/XP only
  • (4,3MB)


Note: All programs (except ezVSP) work under Windows 98 and higher


FAQ & support..

Ask for the price or details:
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Spam protection. How many is five times six?

Question: What is the difference between converters EZL-300W and its Lite version ?
Answer: The EZL-300W Lite corresponds with its properties to EZL-80 module supplemented with a slot for a WiFi PCMCIA card and RS-231/TTL converter. Full version of EZL-300W contains Real-Time Operating System which, along with TELNET, allows setting and changing converter's parameters and firmware via any terminal and thus provides some independence on PC's OS. This is suitable for instance for Linux or UNIX. In addition it contains the EAP-MD5 authentication protocol preventing unauthorized access into WiFi network.

Question: Is it necessary to program the module some way if I only need a simple GateWay from RS-232 (TTL) to TCP/IP or UDP/IP?
Answer: NO, you only need to use the module and set necessary parameters. You don't have to program anything!

Question: Would the module work as a Virtual Serial Port under Windows?
Answer: YES, the converter fully supports the function of remote Virtual Serial Port through TCP/IP. Moreover the producer offers free program ezVSP to download. It's only necessary to register and give the MAC address of the module you've bought.

Question: Is it possible to configure the module also by other means than through Windows programs?
Answer: YES, by the means of AT commands through serial port and any terminal. The sequence of ASCII chars as AT commands can be thus transmitted even from singlechip microcontroller. The list of usable AT commands with examples of correct configuration sequences contains the detailed manual for specific module.

Question:  Is it possible to change a FirmWare in the module ?
Answer:  Yes it is, innovated FirmWares can be downloaded from the Sollae's webpage ( and load into the module via RS-232 and wflash program or via WiFi-Ethernet by the means of the program hotflash.

Question:  Does the ezVSP (Virtual Serial Port) software allow creating more than one virtual port?
Answer:  Yes, this software allows to set up to 127 virtual ports on one PC. Detailed guide on this can be found in the program's manual which is free to download on these pages in menu item "Datasheets".


More Sollae WiFi converters:

  • EZL-80 - incorporated EZL-80 modules (for PCMCIA card) and EZL-80c (for CF card)
  • EZL-90 - kit with an EZL-80c module containing TTL/RS-232 converter, LED indication and power supply
  • EZL-300W Lite - simpler EZL-300W module version