Using Pico’s Serial Devices Over A TCP/IP Ethernet

Introduction

Both PicoLog and Enviromon software support IP networking, this allows our products to be plugged into one or more networked computers, and the data logged from another networked computer (see IP Networking for remote data logging for more information). For some applications having a PC at each point that you wish to collect data is not ideal (problems of cost, size or security). This application note shows how our products can be remotely connected using a ethernet to serial port adaptor.

There are a number of ethernet to serial port adaptors on the market, we used the NPort Express kindly lent to us by Entrix Computing. The NPort Express enables and RS232 devices to be connected directly into an Ethernet TCP/IP LAN or WAN network. To the remote PC, the NPort Express serial port appears as a ‘virtual’ local serial (COM) port.

Using the NPort express any of our serial port products can be used remotely in this way, this application note uses the TC-08 thermocouple data logger as an example, so the instructions will have to be changed slightly if you are using a different product.

Configuring the DE-311 NPort Express

The NPort Express comes pre–configured with a default IP address of 192.168.127.254.
If you are using a public network, such as the Internet, the IP address will have to be changed. This can be done using the Telnet console.

1. Set the NPort Express into RS232 console mode, by setting switch 1 to ‘ON’, 2 and 3 to ‘OFF’.
2. Plug in the power supply (or unplug and then plug back in if power is already being supplied).
3. Connect the NPort directly to COM1 of your computer.
4. Run Hyper terminal and input a new connection name, eg ‘NPort Setup’ and choose OK, as shown in the diagram on the right.
5. Choose ‘Direct to COM1’ and choose OK.
6. Set the port settings, as shown below.
   
7. Type 1, to select ansi/vt100 for console terminal type, and press enter.
   
8. Input the password if required. The connection between the computer and NPort should now be established.
9. Press enter to select [serverConfig].
10. You should now see a window with configurable parameters. Using the Tab key, scroll through to ‘IP Address’ and input the new address.
    
11. Press ‘Esc’ to return to the main menu and select ‘Restart’ to activate the changes.

Using the DE-311 NPort Express With the TC-08

1. Set NPort into Data com. RS232 mode by setting switches 1,2 and 3 into the ‘off’ position (or unplug and then plug back in if power is already being supplied).
2. Plug the NPort Express device server into a spare Ethernet socket and plug in the power adaptor.
3. Install the NPort drivers; consult the NPort user manual for details of how to install for different operating systems.
4. Using the NPort Express Manager Wizard assign the port a number, eg COM3.
   
5. Connect the TC-08 to the NPort, making sure that the following pins are connected.

   TC-08 Pin	RS232	NPort Pin
   2	RX	3
   3	TX	2
   4	RTS	8
   5	GND	5
   7	DTR	6

6. Set up PicoLog to expect the TC-08 on COM3.
7. Set up the channels and start logging data as normal.