Siemens Maxum II Reference Manual page 43

Resets
The SYSCON2.1 has a pushbutton reset switch at the front of the board. This switch may be
accessed via the front of the newest version SYSCON assembly cage. The second connection
consists of two pin connections at the back of the board (top left of the SIB connections photo)
second connection operates using a simple loop closure, and supports legacy SYSCON
assembly cages that provide a separate wired pushbutton reset. Both connections allow the
user to initiate a hard reset of the SYSCON (same as initial power up).
Purge
The purge detect signal is received from the PECM and handled by the SYSCON as a digital
input to generate a purge alarm.
Display Connectors
Interface and power for the Color Touchscreen connect to the SYSCON2.1 using a cable
assembly. This cable runs directly from two connectors on the SIB, out through tthe back of
the SYSCON cage, to the Color Touchscreen panel.
Power
The 24 V power supply mounted beside the SYSCON cage powers the SYSCON2.1 directly
through a cable that plugs into the bottom of the cage. On-board power conversion derives
the other voltages needed for operation.
Note
The real-time clock on the CAC3 board is powered by a backup circuit on the SIB. Older SIBs
may have a battery in the backup circuit. Because the back-up circuit is located on the SIB
board while the real time clock is on the CAC3 board, if the CAC3 board is disconnected from
the SIB, then backup power is lost. The time and date must then be set on the analyzer.
IO Connections
The SYSCON has the following channels:
● x4 digital output relay channels providing a normally closed (NC) and normally open (NO)
with common.
● x4 digital input channels. Straight contact closure and sourcing from the device to trigger
state change is provided. See DI_SINK_SOURCE section for more explanation.
● x2 analog output current channels. Output ranges are 0 to 20mA, 4 to 20mA, 3.8 to 20.5mA
(NAMUR) and 0 to 25mA. The last two are possible with latest versions of software only
(ver 4.3 and later).
DO1 is for system alarms (Fault only) and cannot be addressed.
AO1 is used for the chart recorder but may be used as an AO. If the chart recorder is turned
on it will control the AO's output.
The field wiring is connected to terminals 1 through 12 and 13 through 24.
Maxum II Reference Manual
Manual, 7/2017, 2000596-001
Electronic Compartment Component Descriptions and Maintenance Procedures
2.3 System Controller Version 2.1 (SYSCON2.1)
43