System Overview - Rockwell Automation Allen-Bradley MobileView Terminal Application Technique

Using a MobileView Terminal With Multiple IP20 Junction Boxes

System Overview

The 1734-IB8S POINT Guard I/O input module monitors the contacts of MobileView terminal enabling switch and
stop button, the bypass switch, reset button, and emergency stop (E-stop) for each controlled safety area.
This module can source the 24V DC for all channels to dynamically test the signal wiring for shorts to 24V DC and
channel-to-channel shorts. If a fault occurs, either or all channels are set to 0V DC, and the controller reacts by dropping
out the safety outputs. Only after the fault is cleared and the faulted input device is cycled does the function block (DCS,
DCM or DCSRT) in the controller reset.
Shorts to 0V DC (and wire off ) are seen as an open circuit by the POINT Guard I/O input module, and the controller
will react by dropping out the safety outputs. If the inputs remain discrepant for longer than the discrepancy time, then
the function block in the controller declares a fault. Only after the fault is cleared and the faulted input device is cycled
does the function block in the controller reset.
In this system, the final control device are safety outputs to control motors. The outputs are controlled by a 1734-OBS
POINT Guard I/O safety output module.
In each area near the junction box, there is a reset push button, a bypass switch, and an E-stop safety push button. The
reset push button is to reset fault conditions. The bypass switch is to bypass the junction box and manage the
MobileView terminal. When the MobileView terminal is connected, the bypass switch is set to RUN. When the
MobileView terminal is unplugged (and the junction box must be bypassed), the bypass switch is set to BYPASS. This
two-position key lock switch offers better security than a simple selector switch because it requires a specific key to
activate/deactivate the bypass. The E-stop safety push button is an emergency stop.
The Stratix 5700 managed switch lets you know which Ethernet port is connected to the MobileView terminal.
Figure 1 - System Layout
Compact GuardLogix Controller
MobileView Terminal
MobileView Terminal Connection Cable
(1)
In this publication, the application examples use a Compact GuardLogix controller, but the information also applies to any ControlLogix safety controller.
6
1
2
(1)
Junction Box Area 1
Rockwell Automation Publication 2711T-AT001B-EN-P - February 2017
Guard I/O
Modules (3)
1 10 9
8
2
Stratix 5700
3
7
4
5 6
Junction Box Area 2
1
2
Junction Box Area 3