Basler DGC-2020HD - RS-485 and RS-232 Interfaces; AVR and GOV Control Outputs

2-8 9469300994
Terminals and Connectors DGC-2020HD
Notes
1. If the DGC-2020HD is providing one end of the J1939 bus, a 120
ohm, ½ watt terminating resistor should be installed across
terminals 51 (CAN1L) and 52 (CAN1H) or 54 (CAN2L) and 55
(CAN2H)
2. If the DGC-2020HD is not providing one end of the J1939 bus, the
stub connecting the DGC-2020HD to the bus should not exceed
914 mm (3 ft) in length.
3. The maximum bus length, not including stubs, is 40 m (131 ft).
4. The J1939 drain (shield) should be grounded at one point only. If
grounded elsewhere, do not connect the drain to the DGC-
2020HD.
5. It is recommended to upgrade the firmware in all AEM-2020s and
CEM 2020s that share a CAN bus network with a VRM-2020.
Upgrade CEM-2020s to firmware version 1.01.05 or later.
Upgrade AEM 2020s to firmware version 1.00.06 or later.
RS-485 Interface
DGC-2020HD controllers can be monitored and controlled via a polled network using the Modbus™
protocol. The RS-485 port supports a user-selectable baud rate of 1,200, 2,400, 4,800, 9,600, 19,200,
38,400, 57,600, or 115,200. Seven or eight data bits per character can be selected. Odd, even, or no
parity is supported. One or two stop bits are selectable. RS-485 Modbus supports a single Modbus
Master only. Modbus register values for the DGC-2020HD are listed and defined in Basler Publication
9469300998, Instruction Manual for DGC-2020HD Digital Genset Controller Modbus
®
Protocol. RS-485
interface terminals are listed in Table 2-13.
Table 2-13. RS-485 Terminals
Terminal
Description
56 (RS-485 A)
RS-485 send/receive A connection
57 (RS-485 B)
RS-485 send/receive B connection
58 (RS-485 SHIELD)
RS-485 shield connection
Automatic Voltage Regulator (AVR) Control
AVR control outputs provide control of the generator voltage setpoint. AVR control terminals are listed in
Table 2-14.
Table 2-14. AVR Control Output Terminals
Terminal
Description
64 (AVR +)
AVR control output positive
65 (AVR –)
AVR control output negative
Governor (GOV) Control
GOV control output contacts provide remote control of the generator speed (RPM) setpoint. GOV control
terminals are listed in Table 2-15.
Table 2-15. GOV Control Output Terminals
Terminal
Description
66 (GOV +)
GOV control output positive