Hatteland Display 26 inch - HD 26T21 MMC (Widescreen) - Manual (Page 56)

Specifications - NMEA / IEC COM Module RS-422 / RS-485
PCA100293-1
56
IND100129-138
NMEA RS-422 / RS-485 (ECDIS) module (PCA100293-1):
Suitable for communication with serial protocol based equipment. Connect and secure your cables to the Terminal
Block 3.81 connector. For more information please review the Data Sheet in the Appendix chapter as well as the
“Housing Connector Overview” in this manual.
Note: Our units is based on an isolated RS-485 interface with enhancements to meet NMEA standard. Our unit is
designed to be used with the isolated ground wire connected as shown below. If this wire is not connected, our units is
more sensitive to fast transient voltage at the connectors. (The “isolated Ground” wire will help absorb this energy).
For slow changing or DC offset our system will most likely work without the ground wire. Hatteland Display
recommends connecting the ground wire since it will help protect the system in event of fast transient and most likely
also help improve signal integrity in the system. Please note that if no ground wire is used and the transient dump too
much energy for the ESD logic to handle you will need to replace the NMEA card (If the NMEA card fails due to this it
will not be a warranty repair).
- Black is always connected
- Blue is connected when the device act as a receiver
- Red is connected when the device is acting as a transmitter
PIN 01 & 06 TxD- Transmit Data Negative
PIN 02 & 07 TxD+ Transmit Data Positive
PIN 03 & 08 GND Isolated Ground
PIN 04 & 09 RxD- Receive Data Negative
PIN 05 & 10 RxD+ Receive Data Positive
- Black is always connected
- Blue is connected when the device act as a receiver
- Red is connected when the device is acting as a transmitter
NMEA Standards:
IEC61162-1 chapter 3.5.5 state that the input shall withstand 15V between ground and input. The reference speed
specified is set at 4800 bit/s.
IEC61162-2 chapter 3.1 state that there are 3 wires to be used. (A, B and C). The reference speed for this interface is
set as 38400 bit/s.
Please visit http://www.iec.ch (International Electrotechnical Commission) for the complete standard description.