Matrix Orbital VFD2041 Legacy - Manual (Page 10)

VFD2041 rev 2 10
The RS-232 connector on the PC cable is wired so that a standard “straight through” 9 pin D-sub cable may
be used to connect the module to a standard serial port such as COM ports on PCs. Note that this device
complies with the EIA232 standard in that it uses signal levels from ± 3V to ± 12V. It will not operate
correctly at TTL (0 to +5V) levels.
Pin Number Direction Description LCD Host
2 Data from LCD Data out Tx Rx
3 Data to LCD Data in Rx Tx
5 - Ground gnd gnd
2.2.2 Applying Power via the RS-232 Connector
The power connector on the PC cable is wired as shown in Figure 2-7. Power may be provided to the
module by pin 9 of the DB9 connector instead of through the 4-pin SIP. If power is to be applied using the
DB9, it must be a regulated 5Vdc supply. Note: This applies to wide voltage units (V and VPT
extensions) as well as to standard 5 volt units.
To use pin 9 as the power source, the user must solder the 5 volt jumper pad beside the DB9 connector. If
you have any further questions or concerns don’t hesitate to contact Matrix Orbital at support@matrix-
orbital.com.
Warning: Use this method of power up at your own risk. Application of a voltage to pin 9 greater
than 5.5 volts will cause immediate destruction of unit and void the warranty.
2.2.3 Configuring RS-232 and I
2
C
RS-232 baud rate and I
2
C address are configured by means of jumpers (see ).
Figure 2-8 RS-232 jumpers