IP Serial

When sending a character sequence to a remote serial port connected over Ethernet the packet can be splitted to several smaller packets and each of them can travel a different way, which messes up the timing on the RS-232 or RS-485 serial port.
Some devices controlled over the serial port can require precise timing of the data. This devices than cannot be controled over a common Virtual Serial Port, but you can control them using a special application, which uses the transmition timing of the remote serial port.
The following description is for devices with FirmWare version 2.S and higher:

• PortBox
• PortStore / PortStore2
• Charon 1 - PortBox firmware
• I/O Controller

 
The following functions can be used only under these conditions::

• The communication runs over TCP/IP (T: IP mode TCP)
• NVT commands are enabled (V: NetworkVirtualTerminal On)
• The VIRTUAL PARITY commands support is enabled (&V: Variable Parity On)
• The outgoing packet size for the serial line (Serial Tx) is less then cca 500 character (serial Tx Buffer size)

Commands syntax

The commands have a fixed size of 2 bytes and they use a Virtual Terminal (NVT) and functions for remote parity control (Variable Parity).

• Stop Serial Tx - 0xFE 0x58
• Run Serial Tx - 0xFF 0x58
• Pause Serial Tx 10 ms - 0xFE 0x41
• Pause Serial Tx 20 ms - 0xFE 0x42
• Pause Serial Tx 50 ms - 0xFE 0x43
• Pause Serial Tx 100 ms - 0xFE 0x44
• Pause Serial Tx 200 ms - 0xFE 0x45

 

Pay attention to the 0xFF and 0xFE characters

Beacause of the "NVT" and "Variable Parity" modes support, you need to respect 0xFF and 0xFE characters in the data flow as a prefix for NVT (0xFF) and Variable Parity (0xFE) control. This means, that if you want to send the "0xFF" character to the serial port, you need to send it doubled over TCP/IP.
Example: you are sending "0xFF 0xFF 0x41 0xFE 0xFE" over TCP/IP, but the Charon module will send only 3 characters: "0xFF 0x41 0xFE". If you do not double the FF and FE, they will be processed as a commands!
 

Remote parity control - 9. bit communication

The "Variable Parity" mode is primarily designed for controlling the 9th parity bit for 9-bit communication.
There are two ways of controlling the parity:

• The remote serial port configuration change over NVT
  This way is not very useful, because it does not sychronize the parameter change with the serial port data.
• The parity change for the following character using "Variable Parity"
  This will modify the parity for one following character.

If the VIRTUAL PARITY (&V: Variable Parity On) mode is allowed, you will change the parity for the following character if you insert a 2 byte sequence 0xFE 0x50 before the character.
 

Examples of "Serial Tx delay" usage

We used the Charon 1 module in the "Charon 1 DK" for testing. This is the configuration:
******* WEB51 remote setup ******
*** HW-group.com HW 6.0 SW 2.S #01 ***
*** PortBox I/O ***
MAC Address 00:0A:59:00:9D:AF
=========== IP Setup ============
I: Address 192.168.1.24
J: Port 23
M: Mask 255.255.255.0
G: Gateway 192.168.0.1
===== In IP access filter ======
W: Address 0.0.0.0
N: Mask 0.0.0.0
X: Port 0.0
Y: Port Mask 0.0
== Active (Client/Server) mode ==
S: Send to IP PASSIVE mode
U: Port 23
T: IP mode TCP
V: NetworkVirtualTerminal On
K: Keep connection Off
E: Erase buffer on None

========= Serial Setup ==========
&B: Speed 9600
&D: Data bits 8
&P: Parity NONE
&V: Variable Parity On
&S: Stop bits 1
&C: Flow Control NONE
&R: RS485/RS422 control RTS = On [+8V]
&T: Serial Line Timeout 0 - Off
&G: Char. Transmit Delay 0 - Off
&H: Tx Control Tx FULL duplex
======== Security Setup =========
%A: TCP autorisation Off
%K: TEA key 0:01:02:03:04 1:05:06:07:08 2:09:0A:0B:0C 3:0D:0E:0F:10
%S: TCP/IP setup On
======= I/O Control Setup =======
#T: Trigger AND mask 255
#A: Power Up INIT 189
#B: Power Up AND mask 255
#C: Power Up OR mask 0
#D: Power Up XOR mask 0
#X: KEEP mask 0
#Y: AND mask 255
#Z: OR mask 0
#W: XOR mask 0
============ Other ============
D: Load/Save Settings from/to Flash
R: Reboot

WEB51>
 
The image (original size screenshot is here) shows timing of 3 different macros sent from the Hercules software over TCP connection of the serial port.

• Macro 1 - "123456"
  There has been a delay of 30 seconds and 415ms since SAL232 was launched till the "123456" message was received. This is written on the first line, just before the "123456", which was received as a whole.
• Macro 2 - "1$FE$442$FE$443$FE$444$FE$445$FE$446"
  There has been a delay of 918ms since the previous "123456" message was received, till the "1" character was received (time to click the second macro button). But you can see the obvious space of 100ms between the numbers. Slight diversions are caused by windows timer, which has accuracy of cca 10 ms.
• Macro 3 - "U$FE$45V$FE$45W$FE$45X$FE$45Y$FE$45Z"
  There has been a delay of 1024ms between receiving the "6" and the "U" characters (time to click the third macro button). But you can see the obvious space of 200ms between the numbers. Slight diversions are caused by windows timer, which has accuracy of cca 10 ms.

I/O Controller product offers:

• 8 inputs for voltage 5 to 20V DC
• 8 transistor outputs for voltage circa 12V / 300mA (max. 50V)
• serial port RS-232/485

This application note describes:

• Measuring of voltage 110/230V (2x 230V relays)
  Two 230V relays, contacts are connected to I/O Controller inputs.
• Control of 110/230V voltage (2x 12V relays)
  Two 12V relays, controlled I/O Controller outputs, relay contacts control voltage area 110/230V
• Applications of SW solution
  Overview of application that can be used for control

Note: I/O Controller inputs can be controlled from any contact, for example from button or switch that uses 12V power supply I/O Controller. Here are used Relay contacts for clearness.

Connecting scheme

Details of inputs and outputs connecting to I/O Controller:

• I/O Controller manual
  • I/O Controller pin description (see page 7)
  • Example how to connect light bulb and switch to I/O Controller (see page 7)
• Power for the output relays from external 24V DC power source

Inputs

We connect 2 relay contacts to inputs I.0 and I.4. We use I/O Controller as a power source (typical 12V).

• Connect collective ground of inputs (I.GND) to device ground (GND) - marked (a) in scheme.
• Connect I/O Controller input (for instance I.0) to relay contact (see relay number terminal 14)
• I.0 input connect to power supply (PWR) (see terminal 21)
• Connect contact of the second relay to I.4 - see scheme

 
Outputs

Connect inductor of 2 relays relay to outputs O.2 and O.4. We use I/O Controller as a power source (typical 12V) to control relay.

• Connect output of surge guard (O.COM) to device power supply (PWR) (marked as b in scheme)
  This connection protects I/O Controller from spike of relay inductor.
• Connect I/O Controller output (O.2) to relay inductor (relay terminal A2)
• Connect the second relay inductor (see A1) to power supply of I/O Controller (PWR)
• Connect the second relay controlled from output O.4 same way - see scheme.

 

If you need control output relays to other voltage than I/O Controller device power is (up to 48V DC), check the scheme: Power for the output relays from external 24V DC power source.
 

SDK library control

SDK (Software Development Kit) is available for free upon request to simplify control of I/O Controller. This library will save your time and money for developing own applications for I/O Controller.

SDK consists functions as:

• Network search for I/O Controller (UDP Search)
• Device IP address setting (UDP Config)
• I/O pins control (read bit/byte, set bit/byte)
• Remote setting of serial port parameters (speed, parity, etc.)
• Receive information of I/O Controller input state change without established TCP connection (I/O Controller is TCP client)

The library contains transparent manual describing interface. Examples in different program (MS Visual Basic, Delphi, Borland C++, C# etc.) languages are available for free to illustrate applications of SDK library.

Different program languages examples to control relay

You can use basic program language application to control relay connected to I/O Controller. Sample examples for program languages are available on I/O Controller page for free.

• Relay control over C++
  Simple communication examples with common TCP/IP device in Borland C++ Builder 6.00. The example demonstrates simple terminal client and basic NVT commands (Network Virtual Terminal).


• Relay control over Delphi
  Simple communication example with common TCP/IP device in Borland Delphi 5 demonstrates simple client terminal including basic NVT commands (Network Virtual Terminal) and extention for I/O functions.


• Relay control over MS Visual Basic
  Very simple routines for using NVT commands and TCP/IP device through Winsock in MS Visual Basic 5.0. Very simple commands for remote control of I/O Pins are implemented, TEA not.


• Relay control over Java
  Very simple method to control remote I/O pins via JAVA application. The application can be modify according to your wish


• Relay control over PHP
  Very simple method to control remote I/O pins of I/O Controller. User loads a WWW page from PHP server which takes following actions before response: opens connection to IP address and port, reads values, closes connection to binary device and displays loaded values to the user on the WW page.