Getting Started - Digi Connect ME Integration Kit

Digi RealPort is a COM port redirector or "serial-over-TCP/IP" communications model. Commands and data written to a standard serial port on a PC are intercepted, translated, and sent over the network to the Digi Connect ME module. Similarly, data sent from the Connect ME module over the network is translated so it appears to have been received by a standard serial port. Digi RealPort is completely transparent to the application running on the PC.

Advantages: Works with any software that communicates with a standard serial port without modifying the application. Device drivers are available for all major operating systems. RealPort is an excellent choice if you have an existing device that is connected to a serial port.

Disadvantages: Requires a customer to load the appropriate RealPort driver for the operating system on each computer that will communicate with the device.

TCP is a very reliable communications model. Because TCP is a connection-oriented protocol, one device will be configured as a client and the other will be configured as a server. Connect ME can operate as either a TCP Client or a TCP Server. The Client initiates communications, analogous to initiating a phone conversation by picking up the handset and dialing. The Server waits patiently for incoming connections and answers. TCP can also be run securely using SSL (Secure Sockets Layer). The rule of thumb for determining whether the Digi Connect ME should be configured as the TCP Client or as the TCP Server follows: If the Digi Connect ME is part of a device with a user interface and is typically the initiator of a data exchange, choose TCP Client; if the Digi Connect ME is part of a device that has no user interface and is typically listening for and responding to messages, choose TCP Server. Because the TCP Client usually initiates the conversation, some type of user interface on the TCP Client device is generally used to report errors in creating connections to the TCP Server. The TCP Server typically doesn't report connection failures since it can't know when the Client was unable to connect to it. An example of a Digi Connect ME solution configured as TCP Server would be a power meter connected to a power meter manager application. The application, acting as a TCP Client, initiates conversations with each power meter by sending a request to each one (the meters configured as TCP Servers) asking for the current readings. If the application is unable to connect to a Digi Connect ME module (TCP Server), it might report an error to the user and/or queue up another request for a later reading. An example of a Digi Connect ME solution configured as a TCP Client is a network-enabled airport baggage check-in that initiates a conversation when it has information to send to a backend server (e.g., the passenger to Seattle checked two bags). The server database running as TCP Server can reply back with the information required to print the baggage routing tags.

Advantages: Guaranteed and reliable delivery of messages/packets. Strong security available using SSL services. No device driver required.

Disadvantages: Slightly more difficult to program than UDP or serial (RealPort).

UDP is a "connection-less" protocol, meaning that the Digi Connect ME device can be either the initiator or responder at any particular time. UDP is a good choice when the conversation is very structured, with one device making a request and waiting for the reply. Because UDP doesn't guarantee the delivery of messages, using it in situations where the sender doesn't wait for a particular reply before sending the next request may not be ideal. A good choice for UDP communications is when an application is checking online status of a number of remote devices. Each remote device can be connected to a Digi Connect ME module. Because UDP allows multiple destinations for each message, the application can send one request and listen for each remote device to respond.

Advantages: "Light-weight" networking protocol. Easy to program. No device driver required. Good choice for broadcasting to multiple devices.

Disadvantages: Delivery of messages/packets is not guaranteed. No security option. Order of messages and replies is not guaranteed.

Email (SMTP - Simple Message Transport Protocol) alarms are a good choice when the Digi Connect ME is used to monitor the status of the device it is connected to and when a simple notification via email is all that is needed. An example of alarm notifications is a network-enabled copier running unattended in a public area. Sensors measuring toner level, paper level, and jams in the paper path can be connected to the general purpose inputs of the Digi Connect ME. When a fault condition occurs, a general purpose input would be signaled and an email would be sent to a service technician requesting assistance.

Advantages: Alarms sent via email - no programming required. Good choice for monitoring status of device using GPIO (general purpose input/output) lines.

Disadvantages: Email does not provide a guaranteed reliable communications medium, meaning that email messages sent are not guaranteed to be received.

The Digi Connect ME can be used to control other devices using the GPIO (digital) outputs. An example of using digital output control is a Connect ME module setting the state of relays from a remote location using the network and the configuration applet.

Advantages: GPIO outputs controlled using the via the web interface on the Connect ME - no programming required.

Disadvantages: The communication is manually initiated, meaning the operator must set the output lines when the state needs to change.

1. Choose Serial Ports from the Configuration section of the menu on the left side of the browser.
2. Choose RealPort and make sure the Enable RealPort Server box is checked. It is not necessary to configure Basic serial port settings since they will be set by the application running the RealPort driver.
3. Click the Save button at the bottom of the window.

1. Choose Serial Ports from the Configuration section of the menu on the left side of the browser.
2. Choose TCP and make sure the Automatically establish TCP connections box is checked.
3. If you are using the sample application provided, choose DCD in the Connect field. This will initiate the connection when the DCD line is asserted.
4. Enter the IP address of the TCP Server (the remote device to connect to) in the Connect To field.
5. Enter the port number for the conversation (use 7777 with the sample applications) in the TCP Port number field.
6. Choose Basic and set the serial port parameters to match the device connected to port 1 of the Digi Connect ME development board. If you are using the sample applications and a loop-back plug, you can omit this step.
7. Click the Save button at the bottom of the window.

1. Choose Serial Ports from the Configuration section of the menu on the left side of the browser.
2. Choose TCP and make sure the Enable TCP Server box is checked.
3. Enter the TCP port number for the conversation in the Raw TCP Port field (use 2101 with the sample applications).
4. Click the Save button at the bottom of the window.

1. Choose Serial Ports from the Configuration section of the menu on the left side of the browser.
2. Choose UDP and make sure the Enable UDP Server box is checked if the Connect ME should receive UDP messages. Make sure the Enable UDP Client box is checked if the Connect ME should send UDP messages.
3. If receiving UDP messages, enter the Raw UDP Port value. The default value 2101 should be used for the sample applications.
4. Connect ME can send UDP messages to one or more destinations. If the Connect ME is sending UDP messages, enter the IP address for each destination, enter the UDP Port that the destinations are using, and make sure the Enabled field is checked for each destination. For the UDP sample application set the UDP Port to 7777. Enter the Raw UDP Port value. The default value 2101 should be used for the sample applications.
5. Click the Save button at the bottom of the window.

1. Choose GPIO from the Configuration section of the menu on the left side of the browser.
2. For each of the GPIO pins used for alarms, set the Pin to in.
3. Click the Save button at the bottom of the window.
4. Choose Alarms from the Configuration section of the menu on the left side of the browser.
5. Make sure the Enable sending alarms box is checked.
6. Enter the SMTP server address of the email server to use. In the From field enter the name to use as the email sender.
7. For each alarm defined, make sure the Enable alarm box is checked.
8. Set the Trigger condition for the alarm. To trigger the alarm when the first GPIO line is driven high, set the first checkbox in the trigger condition field to 1. To trigger the alarm when the second GPIO line is driven low, set the second checkbox in the trigger condition field to 0.
9. Enter the Trigger interval. When a trigger bounces in and out of alarm state frequently, you can use this setting to reduce the number of email alarms sent. For example, if an input line triggers three times within one second because of bounce, setting the Trigger interval to two seconds tells the Connect ME to wait two seconds after the first trigger before looking for the next trigger (i.e., one email alert will be sent instead of three).
10. If the Enable reminder notifications box is checked, emails will be sent at the Reminder interval as long as the trigger condition is true.
11. Enter the To, CC, Subject and email Priority fields.
12. Click the Save button at the bottom of the window.

1. Choose GPIO from the Configuration section of the menu on the left side of the browser.
2. For each of the GPIO pins used for output, set the Pin to out.
3. Click the Save button at the bottom of the window.

1. Choose Serial Ports from the Configuration section of the menu on the left side of the browser.
2. Choose TCP and make sure the Enable TCP Server box is checked.
3. Enter the TCP port number for the conversation in the Secure TCP Port field (use 2601 with the sample applications. Note that the only difference between normal and Secure (SSL) TCP Server is the port number.
4. Click the Save button at the bottom of the window.

1. Make sure the Digi Connect ME is configured for RealPort as described in the Configuring Communications Models section.
2. Make sure the RealPort driver is installed on the PC.
3. Plug the diagnostic loop-back plug into port 1 on the Connect ME development board.
4. From the Windows start menu, browse to the HyperTerminal application. Create a new connection and choose the serial port on the Digi Connect ME in the Connect using field. Set the serial port parameters.
5. From the terminal screen in HyperTerminal you can type characters and should see them echoed back with the loopback connected. You can also use the Transfer/Send File feature in HyperTerminal to send and receive data.

1. Make sure the Digi Connect ME is configured as a TCP Client as described in the Configuring Communications Models section.
2. Open the TCP Server sample application to communicate with the Digi Connect ME module configured as TCP Client. A shortcut is created in the Programs/Digi Connect Integration Kit/Samples section of the Windows Start menu.
3. Plug the diagnostic loop-back cable into port P2 on the Digi Connect ME development board.
4. You will see an exchange of messages between the Digi Connect ME module and the TCP Server application running on the PC.
5. See the Readme.html file in the source code directory of the sample for more information.

1. Make sure the Digi Connect ME is configured as a TCP Server as described in the Configuring Communications Models section.
2. Open the TCP Client sample application to communicate with the Digi Connect ME module configured as TCP Server. A shortcut is created in the Programs/Digi Connect Integration Kit/Samples section of the Windows Start menu.
3. Enter the IP address of the Digi Connect ME module when prompted in the TCP Client sample.
4. Plug the diagnostic loop-back cable into port P2 on the Digi Connect ME development board.
5. You will see an exchange of messages between the Digi Connect ME module and the TCP Client application running on the PC.
6. See the Readme.html file in the source code directory of the sample for more information.
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1. Make sure the Digi Connect ME is configured for UDP as described in the Configuring Communications Models section.
2. Open the UDP Serial sample application to communicate with the Digi Connect ME module configured for UDP. A shortcut is created in the Programs/Digi Connect Integration Kit/Samples section of the Windows Start menu.
3. Enter the IP address of the Digi Connect ME module when prompted in the UDP Serial sample.
4. Plug the diagnostic loop-back cable into port P2 on the Digi Connect ME development board.
5. You will see an exchange of messages between the Digi Connect ME module and the UDP Serial application running on the PC.
6. See the Readme.html file in the source code directory of the sample for more information.
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1. Set the switches on SW1 on the development board to the IO1-IO5 positions. This disables the serial signals and enables the use of all five GPIO pins on the Digi Connect ME module.
2. Set the switches on SW2 on the development board to the High positions. This is the ungrounded state for the external connector and is the state that you should normally set for SW2.
3. Make sure the Digi Connect ME module is configured for GPIO inputs and that the alarms are enabled as described in the Configuring Communications Models section. For this example, set GPIO #1 to in and set an alarm on GPIO #1 that triggers on logical level 1.
4. Change switch #1 on SW2 from High to Low and back again. This triggers the email alarms defined.

1. Set the switches on SW1 on the development board to the IO1-IO5 positions. This disables the serial signals and enables the use of all five GPIO pins on the Digi Connect ME module.
2. Set the switches on SW2 on the development board to the High positions. This is the ungrounded state for the external connector and is the state that you should normally set for SW2.
3. Make sure the Digi Connect ME module is configured for GPIO output as described in the Configuring Communications Models section. For this example, set all five GPIO pins to out.
4. Choose the System Information section of the Administration menu of the left side of the browser. Choose the GPIO page of the system information screen. As you change the GPIO settings from asserted to unasserted (and click Set Pins, you will see the state of the LEDs on the development board change.