Sc-Eq Communications Card; Sc-Eq Communication Card Interface Ipu3 - York YVAA Installation Operation & Maintenance

Form 201.47-ICOM1
Issue date: 17/11/2022

SC-EQ communications card

For communication to BACnet MS/TP MODBUS
RTU N2 or LON the SC-EQ Communication Card
must be used.

SC-EQ Communication Card interface IPU3

When connecting the customer BAS, you need to use
terminal TB3 on the 031-03478 board. YorkTalk2 is
the default chiller protocol. The connection for the
communication card is on TB3. See Figure 49 on page
104.
To connect to the network, complete the following
steps:
1. Connect the SC-EQ to Port 1 (TB3) on the 331-
03478-XXX I/O Board as shown.
To access the communication parameters, complete the
following steps:
1. Press the PROGRAM key once.
2. Enter the password 4245.
3. Press the (ENTER) key to access Unit Setup.
Set the following parameters:
1. Navigate to YorkTalk Communication Protocol
Type using the down arrow.
2. Confirm YorkTalk2 is selected.
3. If YorkTalk3 is selected, change to YorkTalk2 and
press the (ENTER) key.
For more details on the SC-EQ to include LON inte-
gration, reference the SC-EQ Communication Card,
450.50-N1.
JOHNSON CONTROLS
Received data (Control data)
The chiller receives eight data values from the SC-EQ.
The first four are analog values and the last four are digi-
tal values. These eight data values are used as control
parameters when in REMOTE mode. When the unit is
in LOCAL mode, these eight values are ignored. If the
unit receives no valid YorkTalk transmission for 5 min-
utes it reverts back to all local control values. Table 13
on page 106 lists the control parameters.
Transmitted data
After receiving a valid transmission from the SC-EQ,
the chiller transmits either operational data or history
buffer data depending on the History Buffer Request,
found in the SC-EQ BAS Points List. Data must be
transmitted for every page. If there is no value to be
sent to a particular page, a zero is sent. Table 10 on
page 106 shows the data values and page listings for
this unit.
SECTION 7 - OPERATION
105
7