Figure 52: I/O Board Relay Contact Architecture - York YLAA0041 Installation Operation & Maintenance

Section 9: Service and troubleshooting
Each output is controlled by the microprocessor by
switching 120 VAC to the respective output connection
energizing contactors, evaporator heater, and solenoids
according to the operating sequence.
120 VAC is supplied to the I/O board via connections
at TB7-1, TB7-6, TB10-1, TB10-6, TB8-1 and TB9-1.
Figure 34 illustrates the relay contact architecture on the
microboard.
TB7
TB7
TB10
TB10
TB8

Figure 52: I/O Board Relay Contact Architecture

192
Data logging to flash
Enabling Data Logging to Flash
The user can enable data logging to an SD card in the
unit setup mode. When data logging is ENABLED or
SKIP UNCHANGED, data is continuously stored at
the programmed data log time on an SD card. The SD
card is in the socket of the 031-02550 I/O board.
Content
SYS 1
TB7-2
COMP 1 The root directory contains directories for each month.
named RMyyyymm, where yyyy is the four digit year
TB7-3 LLSV 1
and mm is the two digit month. Under each monthly
SYS 1
TB7-4
COMP 2
directory, there are the individual daily CSV format-
SYS 1
ted files named yyyymmdd.csv, where yyyy is the four
TB7-5
COMP 3
digit year, mm is the two digit month, and dd is the two
SYS 1
TB7-7
digit day.
HGSV
SYS 1
TB7-8
The first row of the file is the header text. The second
FAN 2
SYS 1
row is the header unit. The remaining rows contain the
TB7-9
FAN 1
data captured at the specified interval of 5 seconds.
SYS 1
TB7-10
FAN 3
If the user disables and then enables the data logging
SYS 2
the same day, the new data is appended to the existing
TB10-2
COMPR 1 (4)
file.
TB10-3 LLSV 2
When the SD card is full, the oldest day of data is de-
SYS 2
TB10-4
COMPR 2 (5)
leted.
SYS 2
TB10-5
COMPR 3 (6)
SYS 2
TB10-7
HGSV
TB10-8
SYS 2
TB10-9
FAN 2
SYS 2
TB10-10
FAN 4
TB8-6
EVAP
PUMP
TB8-7
HEAT EXCH
TB8-2
HEATER
LD12722
Form 150.72-ICOM6
Issue date: 12/19/2023
Johnson Controls