# Presentation: 759864

## T3 WebinarTECHNICAL DEPLOYMENT REVIEW OF THE ITS CABINET STANDARD

**April 4, 2007**

## HOST AND PRESENTER

**THE FED**
**Edward Fok**
- FHWA Resource Center – Operations Technical Service Team
**THE EXPERT (PRESENTER)**
**Ron Johnson**
- Houston TranStar Quality Assurance Engineer
- Co-Chair of the ITS Cabinet Standards Working Group

## PRESENTATION OVERVIEW

**This presentation will show how an existing ITS Standard is actually deployed in the field**
**Meant to be rich in technical contents**
**Intended audience are field engineering personnel**
**Facilitated in part by FHWA’s ITS Standards field support team**
- Encourage better understanding of the Standards
- Help developers create better Standards

## ITS CABINET STANDARD

**Standard Development Organization**
- Institute of Transportation Engineers
- NEMA
- AASHTO
**One of Three Advanced Traffic Controller family of Standards**
- ATC Controller
- ATC API
**Version**
- 1.02.17b
**Currently Deployed by:**
- Houston TranStar (Harris County)
- Farmer’s Branch (Dallas)

## CABINET TYPES

**NEMA ,170 and ITS Cabinets are distinct in size shape and form**
**NEMA Cabinets fall in three sizes M, P and R**
**Typically NEMA enclosures are equipped with shelves to mount the equipment**
**170 cabinets are distinct in that they use 19inch rack system to house the equipment**
**ITS cabinet is designed to accommodate equipment designed for both 170 and NEMA Cabinets**
**The city of Houston uses 170 Cabinets as well as NEMA enclosures, most common being the P-sized Cabinet**

## MAJOR ELEMENTS

**3 different housing types**
**Modular components and Buses**
**Cage assembly**
- “J” Panel
- Shelve Assemblies
- Service Panel Assembly
- Power Distribution Assemblies
- Input and Output Assemblies
- Serial Communication Assemblies
- Cabinet Monitoring Assemblies

**Notes:**
Image of cage assembly

## HOUSING #1 AND CAGE

- Page 165

**HOUSING**

- Page 168

**Notes:**
Schematic of Housing #1 and cage.  Show from front (2-D) and angle (3-D).

## HOUSING #1

**HOUSING #1**

**HOUSING**

**Notes:**
Slides displays two pictures of Housing #1: one from the front and one from the back.

## HOUSING #2 AND CAGE

- Page 165

- Page 168

**HOUSING**

**Notes:**
Schematic of Housing #2 and cage.  Show from front (2-D) and angle (3-D).

## HOUSING #2

**HOUSING**

**Notes:**
Two pictures of Housing #2: one from the front and one from the back.

## HOUSING #3 AND CAGE

**Contain two Housing #1 Cage Assemblies**

**HOUSING**

- Page 166

- Page 168

**Notes:**
Schematic of Housing #3 and cage.  Show from front (2-D) and angle (3-D).

## HOUSING #3

**HOUSING #3**

**HOUSING**

**Notes:**
Slide displays a picture of Housing #3 installed in the field.  The cabinet’s doors are open.  

## ITS CABINET SYSTEM ARCHITECTURE

**SERIAL BUS 1 & 2**

**SERIAL BUS 3**

**ITS CABINET SYSTEM ARCHITECTURE**

**MODULAR COMPONENTS**

**Notes:**
Slide displays a network symbolized by boxes grouped from top to bottom of the slide.  From top to bottom:  Controller, Input Assembly (SIU),  Input Assembly (SIU), Power Distribution Assembly (CMU), Output Assembly (AMU/SIU), Output Assembly (AMU/SIU).  Serial Bus 1 & 2, represented by a red line, connects all boxes.  Serial Bus 3, represented by a blue line, connects the Power Distribution Assembly box, from the CMU, to both Output Assembly boxes through the AMU. 

## “J” PANELS

**Simple side panels made of Aluminum with multiple holes and slots to support various parts and component**
**The type of “J” panels needed are specified by the cage assembly required by each housing**

**J-PANEL**

- Page 173-174

**Notes:**
Slide displays a schematic and a picture of the “J” Panel for Cage 1 Housings 1 & 3 and Cage 2 Housing 2.

## BUS AND SHELVE ASSEMBLY DETAILS

**The bus assembly is hooked on the “J” panel for rear support and attached to the EIA Rail for front support with screws through the slots**
**The shelve assembly is mounted on the "J" panel with bolts in four places for support**

- Page 199

**SHELVE ASSEMBLY**

**Notes:**
Slide displays a schematic of the bus and shelve assembly details. 

## SERVICE PANEL ASSEMBLY

**SERVICE PANEL ASSEMBLY**

- Page 175

**SERVICE PANEL**

**Notes:**
Slide displays a schematic and a picture of the Service Panel Assembly.

## RAW/CLEAN AC POWER ASSEMBLIES

**Provide Raw AC for signaling on Output Assemblies**
**Contains the control of the FTR’s**
**Provides Flasher Power to the load switches during flashing operation**
**120 VAC filtered (Clean) power outlets for cabinet equipment**
**An additional “L” Assembly has been added to make better use of the 14 Pack Output Assembly**

- Page 179-180

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic and a picture of the Raw/Clean AC Power Assemblies

## DC POWER AND COMMUNICATIONS ASSEMBLY

**The DC Power and extension bus provide power for the standard assemblies as well as other optional devices that are used within the ITS Cabinet Platform.  One example would be Ethernet switches that are used for our communications interface.**

- Page 183

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic of the DC Power and Communications Assembly.
Slide displays a picture of the DC Power and Serial Communications Bus Assembly. 

## DC POWER AND SERIAL COMMUNICATIONS BUS ASSEMBLY

**DC POWER AND SERIAL COMMUNICATIONS BUS ASSEMBLY**

**POWER DISTRIBUTION**

**Notes:**
Slide displays a picture of the DC Power and Serial Communications Bus Assembly. 

## DC POWER AND COMMUNICATIONS ASSEMBLY 

**The DC Power and Communications Assembly provides a unique interface for the Serial Busses 1 and 2 for interface between the Controller and the Serial Interface Modules.**

- Page 184

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic and image of the DC Power and Communications Assembly.
Slide displays a schematic and image of the DC Power and Communications Assembly.

## Provides clean power distribution to the Power Supplies and various devices.
Houses 2 Flashers  Control relays, load resistors for the Optical interface and  power contactor for the signals. The CMU (Cabinet Monitor Unit) resides in the PDA and monitors all the control signals from the police panel and flashers. 
House two low voltage DC Power Supplies 24VDC and 12VDC slide out assemblies.
“L” version uses a rack mounted Power Supply functionally the same as the plug in versions. In Housing 1 and 2 a single 24VDC Power Supply is needed.  Housing 3 uses an additional 12VDC Power Supply for power to the Input Detectors. 

**Houses 2 Flashers  Control relays, load resistors for the Optical interface and  power contactor for the signals. The CMU (Cabinet Monitor Unit) resides in the PDA and monitors all the control signals from the police panel and flashers. **
**House two low voltage DC Power Supplies 24VDC and 12VDC slide out assemblies.**
**“****L” version uses a rack mounted Power Supply functionally the same as the plug in versions. In Housing 1 and 2 a single 24VDC Power Supply is needed.  Housing 3 uses an additional 12VDC Power Supply for power to the Input Detectors. **

**POWER DISTRIBUTION ASSEMBLY (PDA)**

**POWER DISTRIBUTION**

## POWER DISTRIBUTION ASSEMBLY

- Page 185

- Cabinet FRONT view

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic of the Power Distribution Assembly from the perspective of the front view of the cabinet.

## POWER DISTRIBUTION ASSEMBLY

- 12-VDC Supply

- 24-VDC Supply

- Cabinet FRONT view

**POWER DISTRIBUTION**

**Notes:**
Slide displays a picture of the Power Distribution Assembly from the front view of the cabinet.  The picture shows the location of the 12-VDC Supply and 24-VDC Supply.

## “L” POWER DISTRIBUTION ASSEMBLY

**The “L” Power Distribution Assembly is mounted at the upper rear on Housing #1 & #3 cages, and at the lower front on the Housing #2 cage.**

- Page 186

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic of the “L” Power Distribution Assembly mounted Upper Rear on Housing 1 & 3 cages and Lower Front on Housing 2.

## “L” POWER DISTRIBUTION ASSEMBLY

**POWER DISTRIBUTION**

**Notes:**
Slide displays a picture of the “L” Power Distribution Assembly.

## POWER DISTRIBUTION ASSEMBLY

- Cabinet REAR view

- Page 187

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic of the Power Distribution Assembly fron the perspective of the rear of the cabinet.

## POWER DISTRIBUTION ASSEMBLY

- Cabinet REAR view

**POWER DISTRIBUTION**

**Notes:**
Slide displays a picture of the Power Distribution Assembly fron the perspective of the rear of the cabinet.

## PDA CONNECTIONS

**Service Connector**

**Raw Power Connector**

**POWER DISTRIBUTION**

**Notes:**
Slide displays two pictures:  one of a service connector, the other of a raw power connector.

## CABINET ELECTRICAL 

**CABINET ELECTRICAL **

- Based on P188

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic cabinet electrical power distribution. 

## CABINET WIRING HARNESS

**The only wiring done within the Housing is the wiring associated with the CC Connector**
**This harness is the same for all types of ITS Cabinet Housing**
**This includes:**
- Fan and light control
- Flash
- Signals On/Off
- Manual Control and Interval Advance
- Manual Stop Time Switch input

- Page 181 - 182

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic of the CC (Cabinet) Connector.

## WIRING HARNESS SCHEMATIC

- Page 211

**POWER DISTRIBUTION**

**Notes:**
Slide displays a schematic of the Wiring Harness.

## Communicate either via contact Closure or Serial data strings via Serial Bus #1
Smart Detectors can be used to send
Vehicle Classification data
Automated Vehicle Location Data/Location data
Speed Information data
100% Compatible with NEMA input detector cards
The entire input assembly with field terminals is a unitary modular unit

**Smart Detectors can be used to send**
**Vehicle Classification data**
**Automated Vehicle Location Data/Location data**
**Speed Information data**
**100% Compatible with NEMA input detector cards**
**The entire input assembly with field terminals is a unitary modular unit**

**CABINET INPUT ASSEMBLY**

**INPUT/OUTPUT ASSEMBLY**

## INPUT ASSEMBLY FRONT AND REAR VIEW

- REAR

- Page 203-204

- FRONT

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays two schematics of the Input Assembly:  one from the front, the other from the rear. 

## CONNECTOR DETAILS

**Removable Field Termination Connectors**

**Test Connector – Reserved for Parallel Wiring**

**Serial Bus Connector**

**Inputs – Manual Control/Door Open/Stop Time/ Flash Sense**

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays two pictures:  one of the Input/Output Assembly that shows the location of the CDC, the Serial Bus Connector, and the Test Connector.  The other picture is of the Removable Field Termination Connectors.

## FOUR INPUT FILES - HOUSTON HOUSING 3

**SIU Connector**

**12 Slots for two-channel devices**

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays a picture of the four Input Files in Houston’s Housing 3.  It shows the SIU Connector and 12 slots for two-channel devices. 
Slide displays a picture of the four Input Files in Houston’s Housing 3.  It shows the SIU Connector and 12 slots for two-channel devices. 

## INPUT FILE (REAR)WITH REMOVABLE CONNECTORS

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays a picture, from the rear, of the Input File with Removable Connectors. 

## Two Versions 6 Position and 14 Position
Provides Cabinet Flash, FTR and Flash Jumpers
System Bus Address supports up to 32 load switches
The entire output assembly with field terminals is a unitary modular unit
The assembly is pre-wired for parallel or serial inputs
The Field Terminals are wired to the AMU for serial monitoring and AC protection
Includes current monitoring if desired

**Provides Cabinet Flash, FTR and Flash Jumpers**
**System Bus Address supports up to 32 load switches**
**The entire output assembly with field terminals is a unitary modular unit**
**The assembly is pre-wired for parallel or serial inputs**
**The Field Terminals are wired to the AMU for serial monitoring and AC protection**
**Includes current monitoring if desired**

**OUTPUT ASSEMBLY FEATURES**

**INPUT/OUTPUT ASSEMBLY**

## 6 POSITION (6 PACK) OUTPUT FILE

- FRONT
- Page 191

- REAR
- Page 192

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays two schematics of the 6 Position (6 Pack) Output File, one from the front and one from the rear. 

## 6 POSITION (6 PACK) OUTPUT FILE

- SIU

- AMU

**INPUT/OUTPUT ASSEMBLY**

- FRONT

- REAR

**Notes:**
Slide displays two pictures of the 6 Position (6 Pack) Output File, one from the front and one from the rear.  The pictures shows the location of the SIU and AMU.

## 14 POSITION (14 PACK) OUTPUT ASSEMBLY

- FRONT
- Page 192

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays a front-view schematic of the 14 Position (14 Pack) Output Assembly File. 

## 14 POSITION (14 PACK) OUTPUT ASSEMBLY

- REAR
- Page 192

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays a rear-view schematic of the 14 Position (14 Pack) Output Assembly File. 

## REAR VIEW

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays a rear-view picture of the 14 Position (14 Pack) Output Assembly File. 

## OUTPUT SOCKET DETAIL

**OUTPUT SOCKET DETAIL**

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays a picture of the Output Socket Detail.  The picture shows the location of the Address Block, the Field Wiring Connector, the FTR Socket, and Lightening Protection. 

## OUTPUT FILE CONNECTIONS

**DC Power Connector**

**AC Connector  Clean Power**

**AC Field Connector**

**Signals - AC Connector**

**Lightning Protector **

**INPUT/OUTPUT ASSEMBLY**

**Notes:**
Slide displays pictures of Output File Connections.  Shown are the DC Power Connector, the AC Field Connector, the Lightening Protector, the AC Connector Clean Power, and the Signals-AC Connector.

## CABINET SERIAL COMM. NETWORK

**SERIAL COMM NETWORK**

**Notes:**
Slide displays the Cabinet Serial Communications Network symbolized by a network of boxes grouped from top to bottom of the slide.  From top to bottom:  Controller, Input Assembly (SIU),  Input Assembly (SIU), Power Distribution Assembly (CMU), 14 Pack Output Assembly (AMU/SIU), 6 Pack Output Assembly (AMU/SIU).  Serial Bus 1 & 2, represented by a red line, connects all boxes.  Serial Bus 3, represented by a blue line, connects the Power Distribution Assembly box, from the CMU, to both Out Assembly boxes through the AMU.   

## CABINET SERIAL COMMUNICATION SYSTEM

**CABINET SERIAL COMMUNICATION SYSTEM**

**Similar to the NEMA TS-2 using Synchronous Data Link Control (SDLC) protocol**
**Serial interface unit  (SIU) is the cabinet communications and control unit**
**SERIAL BUS  1**
- command / response, distributed processing of  outputs and status/detection or status of inputs
**SERIAL BUS  2**
- Collects preprocessed data from sensors or modular  NTCIP devices
**SERIAL BUS 3**
- dedicated to monitor cabinet systems

**SERIAL COMM NETWORK**

**Notes:**
Slide displays the Cabinet Serial Communications Network symbolized by a network of boxes grouped from top to bottom of the slide.  From top to bottom:  Controller, Input Assembly (SIU),  Input Assembly (SIU), Power Distribution Assembly (CMU), 14 Pack Output Assembly (AMU/SIU), 6 Pack Output Assembly (AMU/SIU).  Serial Bus 1 & 2, represented by a red line, connects all boxes.  Serial Bus 3, represented by a blue line, connects the Power Distribution Assembly box, from the CMU, to both Output Assembly boxes through the AMU.

## SERIAL BUS #1

**“****Real-time” communications from Controller to I/O**
**614 kbps communications speed, SDLC frames**
**Command / response protocol with CRC and timeouts**
**Controller “talks” to all devices in cabinet at once**
**Peripheral device “listens” for its address and responds**
**Normally used with Serial Interface Units (SIU)**
**Same protocol as Field I/O (FIO), but at different addresses**

**SERIAL COMM NETWORK**

## SERIAL BUS #1

**Used for real time information required to operate the system**
**Highest Priority**
**Time Sensitive data exchanges**
**Connected to Controller, SIU and CMU**
**Maximum speed 614 kbps**

**SERIAL COMM NETWORK**

**Notes:**
Slide displays Serial Bus #1 Communication Network and how the bus connects to the Controller, Input Assembly (SIU),  Input Assembly (SIU), Power Distribution Assembly (CMU), 14 Pack Output Assembly (AMU/SIU), 6 Pack Output Assembly (AMU/SIU). The image also shows that Serial Bus 3, represented by a blue line, connects the Power Distribution Assembly box, from the CMU, to both Output Assembly boxes through the AMU.

## SERIAL BUS #2

**SB2 located in same cabinet 25-pin “D” connector, CAT5**
**Separate communications channel directly from controller to serial detectors for loop tuning, status, etc**
**Used for long “conversational” messages without impacting I/O update performance**
**Protocol differs with each vendor and hardware device**
**Software driver comes with each hardware device and is installed on 2070 ATC, similar to PC device drivers**
**Anticipates future serial detectors other ITS applications**

**SERIAL COMM NETWORK**

## SERIAL BUS #2

**Use for less critical information between the controller and SIU inputs and outputs**
**For example returning vehicle counts, classification, other info requested by a central system**
**Also for preprocessed data from detector devices or modular  NTCIP devices**
**Max speed of 614.4 kbps**

**SERIAL COMM NETWORK**

**Notes:**
Slide displays Serial Bus #2 Communication Network and how the bus connects to the Controller, Input Assembly (SIU),  Input Assembly (SIU), Power Distribution Assembly (CMU), 14 Pack Output Assembly (AMU/SIU), 6 Pack Output Assembly (AMU/SIU). The image also shows that Serial Bus 3, represented by a blue line, connects the Power Distribution Assembly box, from the CMU, to both Output Assembly boxes through the AMU.   

## Dedicated to communications between CMU and AMU
Used to allow CMU to monitor 
Voltages
Operating Conditions
Currents
To determine actual switch pack conditions
Operates at 153.6 kbps

**Used to allow CMU to monitor**
**Voltages**
**Operating Conditions**
**Currents**
**To determine actual switch pack conditions**
**Operates at 153.6 kbps**

**SERIAL BUS #3**

**SERIAL COMM NETWORK**

**Notes:**
Slide displays a picture of Serial Bus #3.  

## SERIAL BUS #3

**Monitor system bus**
**CMU / auxiliary monitor unit (AMU)**
**Driven by CMU via SDLC protocol**
**Communication uses EIA- 485 standard **

**SERIAL COMM NETWORK**

**Notes:**
Slide displays Serial Bus #3 Communication Network and how the Serial Bus #1 and #2 connects to the Controller, Input Assembly (SIU),  Input Assembly (SIU), Power Distribution Assembly (CMU), 14 Pack Output Assembly (AMU/SIU), 6 Pack Output Assembly (AMU/SIU). The image shows that Serial Bus 3, represented by a blue line, connects the Power Distribution Assembly box, from the CMU, to both Output Assembly boxes through the AMU.   

## SERIAL INTERFACE UNIT (SIU)

**SIU – Microprocessor based communications device**
**Sends and receives SDLC data from SB #1 and SB #2**

**SERIAL COMM NETWORK**

**Notes:**
Slide displays a picture of the Serial Interface Unit (SIU) and the location in the Cabinet. 

## CABINET MONITORING SYSTEM

**Provides a fail-safe mechanism for the entire collection of sub-assemblies**
**Components Include**
**CMU – Conflict Monitor Unit**
**AMU – Auxiliary Monitor Unit**
**Extremely flexible and expandable**
**Allows for response to a conflict at a single intersection and not impact other intersections/ramps/etc operated by same controller**

**CABINET MONITORING SYSTEM**

**Notes:**
Slide displays a diagram of the  Cabinet Monitoring System and its location in the overall cabinet communications network.   

## CONFLICT MONITOR UNIT - CMU

**Housed in the PDA – Main processor of cabinet monitoring**
**Monitors main cabinet functions**
**Cabinet power**
**Door status**
**Status of the Flasher**
**Communicates to other AMU**
**Communicates via Serial Bus #1 to the controller and Serial Bus #3 to the AMU**
**Controller asks for real time status and compares what it thinks it sent to load switches to what is actual happening**

**CABINET MONITORING SYSTEM**

**Notes:**
Slide displays a picture of the Cabinet Monitor Unit (CMU). 

## CMU is addressed so that multiple CMU can be accommodated within one cabinet (Multiple PDA’s)
Addressing is accomplished via the PDA rear programming jumpers

**Addressing is accomplished via the PDA rear programming jumpers**

**CONFLICT MONITOR UNIT - CMU**

**Diode board has been replaced with a serial memory key.**
**Non Volatile computer memory**
**Stores configuration data for the monitor and replaces the diode board**
**During start up sends configuration to controller for checking**

**CABINET MONITORING SYSTEM**

**Notes:**
Slide displays a picture of four serial memory keys.

## CMU BLOCK DIAGRAM

**CABINET MONITORING SYSTEM**

**Notes:**
Slide displays the CMU Block Diagram.

## AUXILIARY MONITOR UNIT (AMU)

**Housed in each output assembly**
**Monitors the outputs (Voltages and Currents) of the switch packs and reports this status to the CMU**
**This allows for flexibility in cabinets**
**Four units are accommodated in this system**
**Normally these devices are all contained in the same cabinet**
**Sends Field status to CMU**

**CABINET MONITORING SYSTEM**

**Notes:**
Slide displays a picture of the Auxiliary Monitor Unit (AMU).

## AMU BLOCK DIAGRAM

**CABINET MONITORING SYSTEM**

**Notes:**
Slide displays the AMU Block Diagram.

## PUTTING IT ALL TOGETHER

**Notes:**
Schematic of Cabinets #1 and #3.

## FIELD INSTALLATION – HOUSING #1

**Notes:**
Slide displays two pictures of field installation of Housing #1—one from the front and one from the back. 

## FIELD INSTALLATION - HOUSING #3

**FIELD INSTALLATION - HOUSING #3**

**Notes:**
Slide displyas three pictures of field installation of Housing #3.  One picture of a technician wiring and installing the housing to its base; another picture of three technicians maneuvering the housing onto its base; a last picture of the housing completely installed. 

## ONGOING/FUTURE INITIATIVES

**High Occupancy Vehicle Control**
**Traffic Incident Management**
**Remote device interrogation and diagnosis**
**Conversion of parallel circuit to pure serial circuit**

## LESSONS LEARNED

**Specification can indeed become reality**
**Housing 3 has been the standard for Harris County since it directly fits on a NEMA “P” foundation allowing deployment with the least cost, since we are able to use existing wiring, conduit and pull boxes and foundation.**
**The modular construction of the assemblies will allow an agency to buy equipment to a base standard then do custom design as needed.**
**In addition to modularity the Conflict Monitoring system is the most comprehensive and versatile hardware yet produced.  **

## QUESTIONS?

**Session transcripts:**
- Email : **edward.fok@fhwa.dot.dov**
- Use subject heading: **ITS cabinet T3 transcript**
- Will contain slides and Q&A
- Available in about two weeks
- Do not submit follow up question with this subject heading
**Standards document and related questions: ****www.ite.org**
**TranStar related questions: RJOHNS8@houstontranstar.org**

## NEXT T3 WEBINAR

**April 5****th**** 13:00 – 14:30 EDT**
**Topic: “ITS System Engineering (SE) for ITS: Using FHWA’s New SE Handbook” (repeat session)**
**Register at:**
- http://www.pcb.its.dot.gov/t3/x070913_se_guide.asp
- Clicking on T3 link on ITS PCB homepage at: http://www.pcb.its.dot.gov
**All T3 webinars are free of charge**

## ACRONYMS

| AASHTO  | American Association of State Highway Transportation Officials | CC  | Cabinet Connector |
| --- | --- | --- | --- |
| AC | Alternating Current | CDC | Cabinet Distribution Connector |
| ACCP | AC Clean Power | CMU | Conflict Monitoring Unit |
| ACP | AC Raw Power | COMM | Communication |
| AMU | Auxiliary Monitoring Unit | CRC | Cyclic Redundance Check |
| API | Application Program Interface | DC  | Direct Current |
| ATC | Advance Transportation Controller | DCP | DC Power |
| CAT5  | Category 5 | EIA | Electronic Industries Alliance |

## ACRONYMS

| EQ  | Equipment | GFI | Ground Fault Interrupt |
| --- | --- | --- | --- |
| FHWA | Federal Highway Administration | GND | Ground |
| FIO  | Field Input/Output | I/O | Input/Output |
| FP | Flash Program  "Block" | IA | Interval Advance |
| FT  | Field Termination | ISO | International Organization for Standardization |
| FTR | Flash Transfer Relay | ITS | Intelligent Transportation System |
| FUC | Flash Unit 1 and 2 | KBPS | kilo bits per second |
| G | Green | MCE | Manual Control Enable |

## ACRONYMS

| NEMA | National Electrical Manufacturer Association | TBS | Terminal Block "Service" |
| --- | --- | --- | --- |
| NTCIP | National Telecommunication for ITS Protocol | TR | Transfer Relay |
| PDA | Power Distribution Assembly | TRANSTAR | Harris County transportation operation agency |
| R | Red | VAC | AC Voltage |
| RC | Resistor Capacitor Filter  | VDC | DC Voltage |
| SB | Serial Bus | Y | Yellow |
| SDLC | Synchronous Data Link Control |  |  |
| SIU | Serial Interface Unit |  |  |