Hardware Support: CTI Acela System
As described in the Acela documentation on the CTI web site
, several CTI modules are
- A CTI Acela module (currently only released with a serial interface) that performs most
of the low-level CTI network management.
- A CTI SmartCAB module which when used on a non-DCC model railroad, controls the trains
in a traditional CAB system. The CTI SmartCAB module is not supported by JMRI.
- A CTI TrainBrain (4 output relays and 4 input circuits).
- A CTI Dash-8 (8 output relays, no input circuits).
- A CTI Watchman (8 input circuits, no output circuits).
- A CTI SignalMan (16 output circuits, no input circuits).
- A CTI SwitchMan (16 output circuits, no input circuits).
- A CTI YardMaster (16 output circuits, no input circuits).
- A CTI Sentry (no output circuits, 16 input circuits).
- A CTI network is usually connected to a computer via a CTI to serial (or CTI to USB)
interface. In this configuration all of the CTI network management must be performed by the
computer. CTI also offers an Acela module (currently only released with a serial interface)
that performs most of the low-level CTI network management. JMRI only supports the CTI
Acela interface (it does not support the direct serial -- nor USB interface).
- A CTI network can be used on either a non-DCC or a DCC model railroad. When used on a
non-DCC model railroad, CTI uses SmartCAB modules to control the trains in a traditional
CAB system. JMRI only supports the CTI system when used on a DCC railroad and does not
support SmartCAB modules.
- CTI input sensor modules (Train-Brain, Watchman, Sentry) support five different types
of input sensors: Infrared, Current Detection, Push-Button, Magnetic Reed Switches, and
Photocell. JMRI now supports all of these sensors.
- CTI input sensor modules support unique configuration of each sensor (inverted,
debounce, threshold). JMRI now allows you to configure this.
If the hardware is connected, nodes (CTI modules) are found automatically at startup.
Nodes can also be defined manually with the Configure Nodes
tool. Either way, don't forget to save them with the "Save" button on the Preferences window (under Edit in the main
The CTI Acela network is a true token passing ring network. Each module has two "four wire
phone jacks". One labelled with a RED circle and the other labelled with a GREEN circle. To
complete the ring, you should connect a straight through four wire cable from the GREEN jack
in one module to the RED jack in the next module. The last cable should connect the GREEN
jack in the last module back to the RED jack in the first module.
The CTI Acela module has the same RED and GREEN jacks as well as a third YELLOW jack. The
CTI Acela module should be placed somewhere in the ring just as any other CTI module.
For the CTI Acela module a special four wire cable should be connected from the YELLOW
jack into the serial port of the controlling computer (or a serial to USB converter).
Once powered on and started, if the red LEDs on each module are not flashing then the ring
is broken (either no power to one or more modules or a bad cable or the cables are daisy
chained wrong or a cable has become loose).
For completeness, on power up, each CTI module has a solid RED led lighted.
Once the Acela network is up, the red LED on each module will flash as a packet passes by
(so you basically see all of the nodes flashing rapidly -- almost in sync).
The Acela module itself is different in that it always flashes a green LED to indicate
that it is happy (whether the ring is happy or not).
Naming of CTI Acela inputs and outputs is described on a separate
Third Party info
More information on the Acela hardware can be found on the CTI web site.