In industrial settings, safety obviously should remain paramount. We asked three industry experts to discuss the key trends that influence the latest advances in safety components.
An important trend has packaging, food and beverage, and automotive industries moving toward more integrated solutions that keep equipment safe, as well as highly productive and easy to maintain and troubleshoot, says Omron Automation and Safety product marketing manager Matt Dodds. "In the past, plants used safety monitoring relay units to monitor metal guards that surrounded equipment, and when the relays opened, it caused the entire process to stop," he says. "Currently, on smaller scales, facilities are replacing relays with standalone programmable safety controllers, which provide numerous capabilities including monitoring, diagnostics, flexibility in programming and zoning of outputs. The controllers typically can be monitored through a network connection to a PLC or HMI, making them easier to troubleshoot. Thus, to maintain integrity, the safety CPU is still a separate entity but is programmed using the same software, which makes system development simpler."
Also Read: Industrial Safety: Asia to Top Market for Machine-Safety Components
That said, relays still play an important role, says Rockwell Automation business director of safety components Brian Taylor, "A growing trend in safety is the proliferation of intelligent, cost-effective, network-enabled, safety components such as advanced relays," he says. "The devices feature integrated networking capabilities and advanced software that provides greater flexibility and access to more operating and diagnostic data. This lets plants meet safety compliance goals more efficiently while supporting their productivity goals. In addition, software advancements let users adjust safety settings without having to change their wiring. The advancements also provide improved visibility of potential issues for quick troubleshooting."
Because the Internet of Things continues to expand in the industrial automation arena, it’s more important then ever for facilities to connect safety within their networks, adds Zachary Stank, product marketing specialist-safety at Phoenix Contact USA. "Previously, this was possible only through a fail-safe PLC," he says. "Currently though, safety technology is growing to include networkable, stand-alone safety controllers and Ethernet-capable relays."
|Programmable Safety Controller
SC26-2 programmable safety controller uses safety function blocks, Boolean logic functions and a user-friendly programming environment for creating safety control logic. The device has 26 input terminals and two redundant, solid-state, safety outputs. Free PC graphical user interface configuration software includes a ladder logic diagram and a text-based summary of all input device and controller output settings. Models are available with an embedded Ethernet node that provides up to 64 virtual status outputs.
|Safety Sensor Signals
EP1908 EtherCAT I/O box has eight 24-Vdc safety inputs, which can be used to connect safety sensors via M12 connectors, allowing the acquisition of safety sensor signals directly on the machine instead of having to mount the safety I/O inside a control cabinet. The EP1908 conforms to IEC 61508 SIL 3 and DIN EN ISO 13849-1 PLe requirements.
XW emergency stop switches feature push-turn and push-pull action. Should the switches be damaged, NC contacts turn off. A bright-green mechanical indicator lets users check latched or normal status from a distance. The E-stops comply with international safety standards and are UL-, c-UL-listed, TUV-recognized, and EN- and CCC-compliant. Illuminated models are available.
|Safety Laser Scanner
OS32C-4M safety laser scanner has a 4-m safety zone and a 15-m warning zone, and EtherNet/IP connectivity to support on-demand, real-time monitoring of operating status, including error diagnostics. Models with data collection functions can be used as an input to measurement or navigation algorithms, without disrupting the safety function. The I/O block can remain mounted when the sensor head is replaced, retaining the original wiring and mounting alignment with no need to reprogram after sensor replacement.
Omron Automation and Safety;
|Protect Your Workers
RVS58S safety encoders and VBA-2E-KE4-ENC-S AS-Interface encoder input modules help ensure workers safe machine access during setup and maintenance. The encoders operate at 5 Vdc ±5% and deliver a maximum output frequency of 200 kHz in operating temperatures ranging from -20 to 80° C. The encoder modules have a compact 22.5-mm-wide housing and snap into place on a standard 35-mm mounting rail. Each module provides two safe inputs for the incremental encoders to monitor the standstill, rotational speed and direction of rotation on up to two axes of motion, and sends a safe signal via the AS-i network when a value falls below a set threshold. The system is suitable for applications that demand SIL3, PLe and Category 4 certification.
|Bridge to Safety
SafetyBridge Technology V3 includes an upgraded safety logic module and a high-density safety input module. The safety logic module connects with up to 16 satellite modules, and allows direct communication between logic modules. The safety input module lets users configure up to eight dual-channel or 16 single-channel safety inputs. V3 lets users visualize the safety program online to see the safe inputs and outputs, instead of mapping status bits in the PLC program. It is rated for SIL 3, Cat 4 and PLe safety levels.
Guardmaster 440C-CR30 safety relay communicates diagnostic data via a built-in Modbus interface to Micro800 controllers, PanelView graphic terminals or CompactLogix controllers. Free software is available for selecting certified safety function blocks for the safety relay. The device meets PLe, SIL3 per EN ISO 13849-1 and IEC 62061 standards.
|Safety Light Curtains
C4000 Palletizer Advanced and M4000 Standard safety light curtains have IP69K housings, suitable for washdown applications, as well as corrosive and other moist environments. C4000 features a 30-mm resolution with a protective height of 1,050 mm. M4000 Standard has scanning ranges from 0.5 to 4 m.
|Only Way to Fail
Simatic S7-1518F fail-safe controller has a Profinet interface with a two-port switch, two Profinet interfaces, and a Profibus interface. The controller accommodates up to 128 drive axes, operates isochronously in 250 µs, has 10 MB of memory and is available with a bit performance of 1 ns.
|Four-Channel Digital Input
750-633/000-003 4F-Ex i DI module is suitable for the connection of potential-free sensors with contacts for use in hazardous environments. The input data for the four-channel module is transferred securely using Profisafe protocols V1 and V2 on one fieldbus line. The 24 mm-wide module is approved for ignition protection class ia.
Dold trapped-key systems use a series of mechanical locks and keys to control access to gates or doors to running equipment or machines, ensuring safe access. They come in standard (SX) or solenoid-locking (ZRH) versions and one- to five-gate sets. Because operators must perform the locking and unlocking, the trapped-key systems provide first-hand, observable safety. Accessories include door actuators, captive safety key sets, key modules for key exchange box setup and tongue key actuators.
SVM4001 monitor provides sensorless, standstill monitoring for machine-guarding applications up to CAT4/PLe, including guard-locking applications to detect that a machine has come to a stop before letting an operator access the area. Monitoring is done by connecting the SVM4001 in parallel with the motor leads and measuring back EMF. It can monitor one- and three-phase ac induction motors, dc motors and variable-speed ac and servomotors. It’s cULus-approved up to 690 Vac.
|Trip If You Must
STA safety trip alarm is certified by exida for safety instrumented systems (SIS) to IEC 61508:2010 for systematic integrity up to SIL 3 and for random integrity up to SIL 2. Engineers use reliability data from the certification to design and verify each safety instrumented function (SIF) in the system. The STA provides an alternative to backing up PLC or DCS soft alarms, serving as a single-use safety logic solver that acts on hazardous process conditions, and provides emergency shutdown and on/off control in SISs.
Platinum Series pushbuttons and switches withstand water jets, water immersion to 1 m, temperatures -20 to 70 °C and resist oils, solvents, and hydrocarbons to meet UL Type 4x, IP66, IP67 and 69K standards. Options include spring-return operator head actuators and pull-to-release, turn-to-release, and turnkey-to-release latch models.
Automation Systems Interconnect;
TRC fully redundant controller has three independent, 100% isolated channels, and each monitors a single process via remote independent sensors, and compares the output results to each other and a user-programmable deviation. The meter has a 51-segment LED automatic tricolor bar graph and four-digit display. Each channel has its own A/D (14-bit), DAC (16-bit), relays, display, power supply (5-48 Vdc or 90-265 Vac) and serial I/O (RS232/485, USB, or Ethernet).
|Solenoid Interlock and More
AZM300 solenoid latching keyed interlocks have a built-in electronic safety sensor and individual coding options, as well as a built-in RFID sensor to detect the actuator and indicate a closed guard. A solenoid locking force of 1,000 N keeps the guard door securely locked until dangerous conditions, which can exist even after removal of power, have receded.
ESL safety escape release consists of a handle and an interlocking module that protects and monitors safety guards, such as doors and flaps on machines. It features transponder-coded safety technology CES, which ensures maximum safety according to EN ISO 13849-1 (Cat. 4/PL e).
|Monitor your safety
DuelcoSC (DSC) modular programmable safety controller monitors several emergency stop buttons and sensors, such as light curtains, laser scanners, photo-optics, mechanical contacts, safety mats/edges and two-hand control buttons. It provides for reduced number of components, easy electrical installation, configuration with logical operations and drag-and-drop software. It’s certified for SIL3, SILcl3, PL e, CAT4.
|Have Some Integrity
PSSR-2 safety interface controller integrity monitors safety switch, mat, edge and bumper products with a 6.8 or 8.2 kΩ, end-of-the-line resistor at Category 3 SIL 2 PLd and EN 13849. It has a manual and auto reset, three output contacts, force guided relays, and two normally open and one normally closed contacts.
Type 4 light curtains provide a multi-beam barrier of infrared light. If any of the beams are blocked by an object, such as a finger or a hand, the light curtain signals the machine to a safe state. The curtains come in protective heights 160–1,510 mm, and in 150 mm increments with optional muting and blanking. Installation doesn’t require software or control boxes, and meets highest maximum achievable safety level requirements of SIL3, SILcl3 and PL e per IEC61496.
HL (hazardous location) receptacle extension threads into the conduit entry of a device in a CI D1 hazardous location, and extends the connector into a Class I Div 2 (CI D2) area where it can be mated with the company’s special connectors. The receptacle eliminates the need for intrinsic safety barriers by providing fully encapsulated housings joined by a welded aluminum armored cable available in lengths to 20 m. The housings resist pressure surges to 6,000 psi.
|Isolators and Converters
ACT20M signal isolators and converters are for thermocouple and RTD signal conversions where auxiliary or output-loop power is available and where range setting by DIP switch is required. Adjustable switch provides access to hundreds of temperature range combinations, selection of outputs, response time and wire-break failure mode. The devices come in both isolating and non-isolating converter versions, eliminating long thermocouple lead wires or RTD cables.
|Time to Go
TD-CSR time-delay control switch relay provides a means to mitigate arc flash danger in local circuit breaker operation by allowing a manually initiated, time-delayed trip or close. A flashing LED notifies the operator of pending trip or close operation and as a warning to evacuate the arc flash area. For safe operation, the control pushbuttons must be depressed for four continuous seconds to activate the 10-second delay.
|Switch On, Switch Off
Food-grade switches are manufactured using 316 stainless steel, and include mechanical keyed interlock switches, non-contact sensors, explosion-proof sensors and IP69K sensors. The line includes e-stop rope pull switches and enclosures.
ABB Jokab Safety;