aerl
COMMS MANUAL
COOLMAX SR
Australian Energy Research Laboratories, Pty.Ltd
AER07.004 – Version G2 v9
13
th
January 2016
17 of 21
Figure 7 - CAN Connector (6-Way Screw Terminal)
4.2 CAN WIRING
The CAN data lines (CAN-H and CAN-L) must be implemented with twisted-pair wire for proper
data integrity. The wire should have a characteristic impedance of 120 Ω.
Power should also be provided along the CAN cable, ideally with another twisted pair to minimise
noise pickup. An overall shield can also be advantageous.
The recommended choice of cable is 7mm DeviceNet CAN-Bus 'thin' cable, with 24 AWG (data) +
22 AWG (power) twisted pairs and a braided shield. Using this cable will result in a robust
installation.
Standard CAT5 network cabling (which has an impedance of 100 Ω) can be used, but may become
unreliable in longer networks or in the presence of electrical noise from DC/DC converters and other
electrical devices in the system.
With the access cover removed, three terminal blocks should be visible. The left most terminal block
(J1)
is for the alarm output, remote shutdown input, and temperature compensation. The terminal
block
(J3)
on the right is for the Controller Area Network (CAN). The central terminal block
(J2)
is
for power in and power out. Figure 8 and Table 1 below show the PIN-outs for these terminals.
Figure 8 - Terminal Board PINout (Looking into Access Port)
Important
