Johnson Controls CK721-A Hardware Installation Manual

CK721-A Network Controller Hardware Installation
24-10025-237 Rev. –
4
Setting the End-of-Line Switch
Network devices at either end of the RS485 network must be set as network terminated devices.
This is done with the use of the End-of-Line (EOL) switch. The CK721-A module has two EOL
switches, one for each RS485 connector. The CK721-A is shipped with the EOL switches in the
factory default position, which is on (up).
NOTE: Before changing the EOL position, remove the 24VDC supply power to the CK721-A and wait
for the RUN LED to go off.
Replacing the Lithium Battery
The lithium battery is shipped from the factory charged and operational.
If there are no power outages, change the battery every five years. If a power outage occurs, the
battery life is approximately 30 days. Replace with Panasonic® part number CR2025 or
equivalent.
IMPORTANT: Before you replace the lithium battery (recommended every five years or after extended
use), ensure AC power or backup battery power is supplied to the CK721-A. If AC power or backup
battery power is not supplied before you remove the lithium battery, the realtime clock will be incorrect.
LEDs POWER ON is steady when power is applied.
FAULT OFF indicates normal operation, ON indicates a general fault.
RS485 A Flashes/flickers to indicate data transmit.
RS485 B Flashes/flickers to indicate data transmit.
ETHERNET Flashes/flickers to indicate data traffic on the Ethernet connection. OFF
indicates no Ethernet data traffic, and probably indicates a dead Ethernet
network or bad Ethernet connection.
10/LINK ON indicates 10 Mbit connection is established.
100/LINK ON indicates 100 Mbit connection is established.
RUN This LED is currently not used (always OFF).
End-of-Line
Switches
Two End-of-Line (EOL) switches. See Setting the End-of-Line Switch on page 4.
Table 3: Major CK721-A Components
Component Description
RS485 A RS485 B
EOL switch
for RS485 A
EOL switch
for RS485 B
O
N
CAUTION: Risk of Explosion.
Replace the battery with a lithium battery of the same type and voltage rating. Dispose of
the used battery in accordance with local, national, and regional regulations. Failure to
replace the battery with one of the same type and voltage rating may result in an explosion
causing personal injury and property damage.

Johnson Controls CK721-A Specifications

General

Brand	Johnson Controls
Model	CK721-A
Category	Controller
Language	English