Making serial cables

The purpose of this tutorial is to clarify the assembly of the DB9 serial to "5 Pin MTA connector" cable used in FabLab. I hope it is clarifying.

Schematics

First thing is to know what connect to!

Thanks to Jan we have these beautiful drawings of the connectors and the connection.

Connectors MTA 4 pins MTA 5 pins and DB9 9 pins. http://www.fablab.is/w/index.php/Image:Wires.png

Cable connections. http://www.fablab.is/w/index.php/Image:Wires2.png

Materials

• One female DB9 serial connector
• One 5 Pin MTA connector
• Flat cable with 5 wires
• Wire Cutter
• Vice!

5 Pin MTA Connector

Note: Start by the 5 pin MTA connector because it is easier to do this with the wire order of the flat cable.

Put the wires over the blades corresponding to the pins we want to connect to and press them a little bit so that they hold.

Important: Check if the wire exits the connector in the same direction that it exits the board. Important: Leave a 3 cm tip on the other end of the connector. It could be useful to troubleshooting.

Place the back shell and do a lot of pressure. From my little experience we need to do a lot of pressure, we used the panavise existing in the lab to "pressurize", but be carefull so that you don't brake the connector!

Use the panavise to make a lot of pressure in the connector.

DB9 connector

Pass the cable in the strain relief. Don't forget!

Spread the wires in one tip of the flat cable for about five centimeters.

Put the wires over the blades corresponding to the pins we want to connect to and press them a little bit so that they hold. Note: Check if the wire exits the connector in the same direction that it exits the board. Note: Leave a 3 cm tip on the other end of the connector. It could be useful to troubleshooting.

Place the back shell and do a lot of pressure until you hear a click.

Place the strain relief over back shell the connector and do some pressure until you hear a click.

The cable is done!

Know one must check if it is well connected.

Troubleshooting

Place a male connector to the female db9 to access easily to the pins. Also place a male connector in the MT5 connector for the same reason. Then with a multimeter as an Ohmmeter, check for continuity in the corresponding pins.

Connect a male connector

Check for continuity in the corresponding pins with a multimeter as an Ohmmeter.

If you don't have continuity it can be one of two things.

• Misplacement of the wires in the pins. Check the other pins were you were not supposed to have any continuity.
• Not enough pressure in the back shell of the connector and therefor no contact. To check that remove a little bit of isolation of the excess cable that was left before, and measure continuity between this tip and the pin in the back of the auxiliary male connector. If you don't have continuity press a little harder and check again.

Remove a little bit of isolation of the excess cable that was left before,