Pinnacle Systems STTS - Manual (Page 7)

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SYSTEM OVERVIEW
Together with a new patented mat technology, eliminating internal metal plates, and the STTS control
using diverse redundant technology, Pinnacle Systems has achieved a system compliant with OSHA,
ANSI, and the European standards EN954-1 & EN1760-1. These standards dictate safety of machinery-
related parts of control systems and pressure deflection sensitive protective devices and focus on
creating a fault tolerant system. All safety related faults cause a lockout condition requiring internal reset.
The STTS Metal Box Controller system can be ordered with 1 to 3 separate output zones, each with 3
separate isolated dry contact outputs and user option external relay checking for each zone. Up to 8
separate mat inputs allow any combination of mats to control any combination of zones and at the same
time provide instant information of mat faults via a scrolling diagnostic message display and LED's.
DEVICENET industrial data network is optionally available.
In addition to the above-mentioned compliance with various standards, the STTS DIN-rail controller has
been evaluated and approved by the CSA (for electrical safety only). The STTS Din-Rail controller
system comes standard with 1 output zone (2 safety relays, 1 form C auxiliary relay, and 1 fault relay),
external relays checking, and inputs for up to 4 mats. Diagnostic messages are the same as the metal
box, but the din-rail allows for an optional remote diagnostics display. DEVICENET industrial data
network is optionally available.
CIRCUIT DESCRIPTION
Low voltage DC signal (+20VDC & -20VDC) is pulsed out to the mat through two wires. The wires attach
to the top and bottom (internally) of the mat and any force on the mat lowers the resistance between the
two wires causing a drop in voltage. A second pair of wires coming back from the mat is used to sense
this drop in voltage. The redundant circuits compare the voltage to a reference and shut down the zone
when the voltage drops below the reference. The circuit goes through a self-check to verify that the
reference, comparators, mat, wiring, and other circuits are all functioning normally every time it scans a
mat input. Diverse redundant technology, provided by two different computers, controls the whole system
and allows more system flexibility (i.e., diagnostic message display).
METAL BOX CONTROLLER
POWER SUPPLY BOARD
This system is capable of running off of 120VAC or 240VAC or 24VDC input and contains the
circuitry for up to 3 zones (a total of 9 force-guided contact relays) and external relay checking.
This board is connected to the computer board via a 34 pin plug-in header (J6).
COMPUTER BOARD
This board contains two computers, circuitry for eight separate mat inputs, connectors for
diagnostics display, LED's, and push-buttons.
DISPLAY BOARD
This board contains the Diagnostics display, mat input LED's, and zone output LED's.
DIN-RAIL CONTROLLER
The Din-Rail controller is actually 1 circuit board broken up into 3 boards. All 3 boards are linked
via right angle connectors. The Power input is strictly 24vdc as well as all other inputs. Outputs
come from 4 relays that provide dry contacts up to 30vdc.