Site Controller Unit and Trunk Interface Unit

Site Controller Unit (SCU) The SCU is the “Traffic COP” of the system. It is used to direct inbound and outbound signals, with different protocols, to the correct devices. It can support inbound communications from RS-232 or RS-485 sources. Up to 1000 SCU’s, with 100 Access Points on each can be controlled by a single computer. Works with Millenium Windows Software only.

SCU Spec’s Voltage: 9-14 VDC (SCU will not operate below 9 VDC). Current: 90 mA (worst case consumption, board only). Data Storage: 24hr minimum clock and memory backup. Output: 1 Form “C” relay for communications failure. Tamper: The SCU comes with an integrated tamper switch. Data I/O: 1 RS-232 and 1 RS-485 communications port. Network Data: 1 RS-485 port for communications with DCD’s, RCD’s, and ECU’s Operational Temperature: 14ºF to 104 ºF (-10 ºC to 40 ºC)

Addressing the SCU

SCU J1 Terminal Block Connections

SCU J2 Terminal Block Connections

SCU J3 Connector

SCU J4 Terminal Block Connections

SCU J5 Terminal Block Connections

SCU Functionality Switch Settings

SCU Firmware Revisions

Deleting Programmed Data in the SCU

SCU Watchdog LED

SCU Trunk Communications

SCU Input Power

RS-232 I/O for Modems/Direct Connects

SCU Computer Application

SCU Modem Application

SCU Trunk Communications Relay

SCU 50 Hz AC-Clock Sync

SCU Tech Notes If multiple SCU’s are used in the same building, and a single communications node is employed (i.e. RF modem, short haul modem, etc) then a TIU must be used. Make sure the S5 switch settings are selected correctly for the type of communications that is desired. If the DB-9 serial port found on connector J3 is employed, then the device connected to it must communicate at a maximum of 9600 baud. If a modem is connected to the J3 connector, then it must be programmed for auto-originate mode.

SCU Tech Notes Every SCU installed must have at least one Power Supply with the Line Conditioner connected to it. SCU addressing must start with 000. Each SCU can communicate up to 5000 ft on the data trunk to DCD’s, RCD’s and ECU’s. The SCU does not come with an enclosure, make sure that you order one. The inbound data trunk cable and the power cable should have some form of identification like a piece of electrical tape around the jacket to ensure that future trouble shooters know which direction the power and data source is feeding from.

SCU Tech Notes The inbound and outbound shield of the trunk data cable, should be twisted together and fastened with an electrical crimp or wire nut. The shield should not connect to any terminals of the SCU PCB. Inbound and outbound data trunk connections should be made on terminals 1 and 2 (respective of polarity) on the J1 connector. Since the 12 AWG power cable is difficult to install under the terminals of the SCU, it is recommended that the inbound and outbound cables be combined with an 18 AWG pigtail which is wired to terminals 1 and 3 of the J5 connector.

SCU Terminal Summary Label

Trunk Interface Unit (TIU) Data that is transmitted and received via the serial COM Port of a computer or via a modem communications port uses an RS-232 communications protocol. This protocol has a 50 ft cabling limitation between devices. The TIU is used to convert RS-232 to an RS-485 communications protocol. The RS-485 protocol has a cabling capability for up to 5000 ft. This is especially important when the project involves a multi story building or a large scale facility.

TIU Spec’s Voltage: 9 VDC, AC to DC Converter. 120 VAC, 60 Hz, (P/N 125-507148) 220 VAC, 50 Hz, (P/N 125-507147) No Standby Power. DB-9M Connector (RS-232 Connection). RS-485 Output: 0 to 4.0 VDC on the +TXR Line. 0 to 4.0 VDC on the -TXR Line.

TIU Front Panel Lights

TIU Connections Note: When using the TIU with Windows based software, remove the jumper between the ECHO terminal and the Ground terminal.

Connections Between SCU and TIU

SCU’s with Multi Floor Application

TIU Tech Notes The shield for the cable leading to the TIU must be bonded to the shield of the data trunk going to the DCD’s. When using a TIU for a communications backbone, the maximum cabling distance from the first SCU to the last SCU is 5000 ft. There are only two time when a TIU is needed on a system: When the SCU is more than 50 ft. from the computer. When more than one SCU in a single building needs to be hardwired directly to a computer.