Honeywell Low VoltageTerminal Block (Euro style) Note 3 900TEK-0101
Controller Module
C30 and C30S, C50 and C50S, C70 and C70S, C75 and C75S Controllers share the same features, with exceptions
noted.
1 CPU model number (C30 and C30S, C50 and C50S , C70 and C70S, C75 and C75S).
2 Lithium battery (battery tray), which is readily accessible for field replacement. Battery tray on
Controllers C30/C30S, C50/C50S, C70/C70S, and C75/C75S.
3 Serial Interface Ports
For legacy systems, two serial ports, S1 and S2, each configurable as RS-232 or RS-485 provides
interfaces to a PC, external modem, Modbus devices or Operator Interfaces.
For new systems, two galvanically isolated RS-485 serial ports, S1 and S2 provide interfaces to PC
using RS-485 to usb cable. External modem or Modbus devices may be interfaced using RS-485 to
RS-232 converter. RS-485 interfaces to PC, Control Stations or Modbus devices/host.
4 Ethernet LED status indicators
for communications functions
Figure 12 – Controller Module
5 Connection to I/O port of
Scanner Module.
C50/C50S/C70/C70S,
C75/C75S only
6 Second Ethernet (E2) Host
Connection to PC applications
or peer HC900 controllers.
C70/C70S/C75/C75S only
7 First Ethernet (E1) Host
Connection to PC applications
or peer HC900 controllers
8 LED status/diagnostic indicator
for serial port S2 (left)
9 LED status/diagnostic indicator
for serial port S1 (right)
10 LED status/diagnostic indicator
for controller module
11 Mode switch (Pgm, Run/Pgm,
Run). Not present on
C75/C75S; see RSM
Redundant controller rack contains two C75s or C75Ss. Left CPU is designated CPU-A, right CPU is CPU-B; either
CPU can be Lead.

Redundancy Switch Module (C75/C75S only)
The Redundancy Switch Module (RSM) is shown in Figure 13.
It sits between C75/C75S controllers in the redundant controller rack. Left Controller is
designated
“CPU-A”; right Controller is “CPU-B.” Features include:
1. Lead/Reserve controller status indicators.
2. Keyed switch for manual changes to controller modes or to facilitate a Manual Fail
Over.
Figure 13 – Redundancy Switch Module
Scanner 1 Module (S50/S50S only)
900S50, Scanner1 module is shown in Figure 14.
It sits in the I/O rack and provides the link between the controller and
remote I/O. Features at the front of the module include:
1. LED status/diagnostics indicator for scanner functions.
2. One private Ethernet 10/100 Base-T Port; connects to the I/O
expansion port on Controller Module (or to a port on a Switch that
connects to the Controller Module)
3. LED status/diagnostic indicators for communications functions.
Scanner 2 Module (S75/S75S only)
900S75, Scanner 2 Module is shown in Figure 15.
The dual ports provide redundancy through the 2 CPUs. Features at the front of
the module include:
1. LED status/diagnostic indicator for scanner functions.
2. I/O port A. Private Ethernet 10/100 Base-T Port. Connects directly to I/O port
on CPU-A (or indirectly through a switch).
3. I/O port B. Private Ethernet 10/100 Base-T Port. Connects directly to I/O port
on CPU-B (or indirectly through a switch).
4. LED status/diagnostic indicators for communications functions
Figure 15 – Scanner 2 Module
Input/Output Modules
I/O module types:
16 point high level analog input module: each point is configurable for V or mA. Point-to-point galvanic
isolation, chassis to input galvanic isolation.
4 point galvanic isolated analog output module: Supports
from 0 to 20mA each, chassis to output galvanic isolation.
8 or 16 point analog output module: Supports from 0 to
20mA each. Galvanically isolated in groups of 4 channels,
galvanically isolated chassis to output channels.
16 point digital input modules: Contact closure type, DC
voltage and AC voltage types. Galvanically isolated chassis
to input.
32 point digital input module: DC voltage. Galvanically
isolated in two groups 1-16, 17-32. Galvanically isolated
chassis to input channels.
8 point AC (sourcing type) or 16 point DC digital output
modules (sinking type). Galvanically isolated output
channels to chassis and channel to channel in two groups.
32 point digital output: DC voltage (sourcing type).
Galvanically isolated output channel to chassis and
output to output in two groups.
8 point relay output module: four form C type and four form A type relays. Galvanically isolated output
to chassis and output to output.
8 point Universal Analog Input module. Galvanically isolated input to chassis and input to input. With
the exception of RTD types which has four groups of isolation 1-2,3-4,5-6,7-8.
4 channel Pulse/Frequency/Quadrature I/O module. Galvanically isolated channel to chassis.