Non-Contact Inductive Couplers Provide Wiring Advantages, Added Flexibility and Cost Savings Over Industrial Multi-Pin Connectors

Today, engineers are adding more and more sensors to in-die sensing packages in stamping applications. They do so to gain more information and diagnostics from their dies as well as reduce downtime. However, the increased number of sensors also increases the number of electric connections required in the automation system. Previously, the most common technique to accommodate large numbers of sensor in these stamping applications was with large, multi-pin connectors. (Figure 1)

Figure 1
Figure 1: A large multi-pin connector has been traditionally used in the past to add more electronics to a die.

The multi-pin connector approach works in these applications but can create issues, causing unplanned downtime. These problems include:

    1. Increased cost to the system, not only in the hardware itself, but in the wiring labor. Each pin of the connector must be individually wired based on the sensor configuration of each particular die. Depending on the sensor layout of the die, potentially each connector could need to be wired differently internally.
    2. A shorter life span for the multi-pin connector due to the tough stamping environment. The oil and lubrication fluids constantly spraying on the die can deteriorate the connectors plastic housings. Figure 1 shows the housing starting to come apart. When the connector is unplugged, these devices are not rated for IP67 and dirt, oil, and/or other debris can build up inside the connector.
    3. Cable damage during typical die change out. Occasionally, users forget to unplug the connectors before pulling the die out and they tear apart the device. If the connector is unplugged and left hanging off the die, it can be run over by a fork truck. Either way, new connectors are required to replace the damaged ones.
    4. Bent or damaged pins. Being mechanical in nature, the pin and contact points will wear out over time by regular plugging and unplugging of these devices.
    5. A lack of flexibility. If an additional sensor for the die is required, additional wiring is needed. The new sensor input needs to be wired to a free pin in the connector and a spare pin may not be available.
Figure 2
Figure 2: Above is a typical set up using these multi-pin connectors hard-wired to junction boxes.

Inductive couplers (non-contact) are another solution for in-die sensors connecting to an automation system. With inductive couplers, power and data are transferred across an air gap contact free. The system is made up of a base (transmitter) and remote (receiver) units. The base unit is typically mounted to the press itself and the remote unit to the die. As the die is set in place, the remote receives power from the base when aligned and exchanges data over a small air gap.

The remote and base units of an inductive coupler pair are fully encapsulated and typically rated IP67 (use like rated cabling). Because of this high ingress protection rating, the couplers are not affected by coolant, die lubricants, and/or debris in a typical stamping application. Being inherently non-contact, there is no mechanical wear and less unplanned downtime.

When selecting an inductive coupler, there are many considerations, including physical form factors (barrel or block styles) and functionality types (power only, input only, analog, configurable I/O, IO-Link, etc…). IO-Link inductive couplers offer the most flexibility as they allow 32 bytes of bi-direction data and power. With the large data size, there is a lot of room for future expansion of additional sensors.

Adding inductive couplers can be an easy way to save on unexpected downtime due to a bad connector.

fig 3
Figure 3: A typical layout of an IO-Link system using inductive couplers in a stamping application.

From Design and Build, to Operation and Maintenance, IO-Link Adds Flexibility

With almost twelve million installed nodes as of 2019, IO-Link is being rapidly adopted in a wide range of industries and applications. It is no wonder since it provides more flexibility in how we build and maintain our machines and delivers more data.

Design
As an IEC standard (IEC 61131-9), IO-Link provides consistency in how our devices are connected and integrated. With an already large and ever growing base of manufacturers providing IO-Link devices, we have an incredible amount of choice when it comes to what vendors we use and what devices we incorporate into our systems, all while having the confidence that all of these devices will work and communicate together. Fieldbus independent and based on a point-to-point connection using standard 3 and 4 wire sensor cables, IO-Link allows designers to replace PLC input cards in the control cabinet with machine-mounted IO-Link masters and input hubs. This technology means we are drastically less limited in how we design our machines.

Build/Commissioning
IO-Link is well known for simplifying and reducing build time of machines. Standardization of connections means that readily available double ended quick disconnect sensor cables can replace individually terminated wires, and analogue devices and devices using RS232 connections can be replaced with IO-Link devices which connect directly to a machine mounted IO-Link master or IO hub. Simplified wiring along with delivered diagnostics leads to greatly simplified network architecture and reduced build/commissioning time, as well as increased trouble shooting ability. This all leads to reduced hardware and labor cost.

When it comes to the software side of things, you might think that all of this additional functionality and flexibility increases the burden on programmers, however through the use of configuration files provided by the device manufacturers for both the IO-Link devices and the PLC, this additional functionality and data is at our fingertips with minimal time and effort. With the large adoption of IO-Link and growing manufacturer base comes great amounts of reference material, videos, example programs, and support, all of which can help to get our systems up and running quickly.

Operation
When it comes to operation IO-Link opens a world of possibilities. Bidirectional communication of not only process data but diagnostics and parameter data delivers real time visibility into the entire system during operation all the way down to the device level. Things like automated or guided changeover become possible, for example if a manufacturer produces two different parts on the same line, after the production of part A, devices can be reparameterized for production of part B with the push of a button.

Maintenance
Maintenance sees massive benefits from IO-Link thanks to reduced unplanned downtime through device diagnostics which allow for predictive maintenance practices. If a device does get damaged or fails at an inconvenient time, the issue can be found much quicker and be replaced. Once the IO-Link master recognizes that the device was replaced with the same hardware ID, it can automatically reparameterize the device.

IO-Link is already making our lives easier and providing manufacturers with more possibilities in their automated systems, and as we push into Industry 4.0 it continues to prove its value.

For more information on IO-Link and Industry 4.0 visit www.Balluff.com

 

Flexibility Through Automated Format Changes on Packaging Machines

Digitalization does not stop at the packaging industry. There is a clear trend toward more individual packaging and special formats. What does this mean for packers and packaging machine manufacturers? The variants increase for every single packer, and this leads to a decreased batch size. The packer needs highly flexible machines, which he can easily adjust to the different formats and special variants. The machine manufacturer, in turn, must make these flexible machines available. What does this format change look like? Which technologies can support the packer optimally?

There are two different format adjustment tasks to perform. One is the adjustment of guide rails, side belts or link chains so that they can be adapted to the new format. The other is the changing of parts when a new format is to be produced.

Both tasks have different demands concerning automation technology and therefore there are different solutions available.

Format adjustment

Format adjustment is the adjustment of guide rails, side belts or link chains. In order to carry out this adjustment quickly, safely and error-free, precise position information is required. This recorded position information can then be used to support manual adjustment on the display unit or it can be transferred to the PLC for fully automatic adjustment. One possible solution is to use different position measuring systems. Various standardized interfaces are available as transmission formats, including IO-Link.

Fast format changes in secondary packaging.png
Fast format changes in secondary packaging

IO-Link has ideal features that are predestined for format adjustment: sufficient speed, full access to all parameters, automatic configuration, and absolute transmission of measured values. This eliminates the need for time-consuming reference runs. Since the machine control remains permanently traceable, the effort for error-prone written paper documentation is also saved.

One example for a non-contact absolute position measuring system

BML SL1, IO-Link

A magnetic encoded position measuring system is ideally suited for position detection during format adjustment. It is insensitive to dust, dirt and moisture, offers high accuracy and a measuring length of up to 8,190 mm. Therefore, the position determination and the speed control during the change of guide rails, sidebands or link chains are no problem.

For more information read our previous blog post “Boost Size-Change Efficiency with IO-Link Magnetic Encoders and Visualization”.

Changeable part detection

When changing to a different format size, it is often necessary to not only adjust guide rails but to also replace changeable parts. Machines are becoming more and more flexible, which means that the number of changeable parts per machine is growing.  It is becoming increasingly difficult for the machine operator to find the right part and even more difficult to find the correct mounting position. This conceals some avoidable sources of error. If the replacement part is installed incorrectly, it can cause machine damage, which can lead to downtime.

Therefore, a fast recognition of changeable parts is all about reliably detecting the changeable part at the correct position in the machine. It is also important to make it as easy as possible for the operator to detect possible faults before they happen via a visualization system.

One way of identifying exchangeable parts is industrial identification with RFID.

The right part at the right position

When changing a machine over to a new format you can use RFID data carriers or barcodes to ensure that the correct new parts are being used. Vision sensors also detect whether the part was installed correctly or incorrectly. These solutions help you prevent errors and machine damage, which in turn increases throughput and reduces production costs.

Implement predictive maintenance

With RFID data carriers, the operating times of each change part can be documented directly on the part itself. If a part needs to be cleaned, replaced or reworked, a notification or alarm is issued in the machine controller before fault conditions can arise. RFID data carriers also allow regular cleaning cycles to be logged.

Automate machine settings

Since you can store the individual setting parameters for the change part on the data carrier, the part itself also provides the information to the machine controller. Thus, the change part can trigger a format change in the PLC and change the production process. This is an important step toward intelligent production in the Industry 4.0 concept.

Simple visualization enables expert free operation

With an LED signal lamp, the operator can recognize the operating status of the machine quickly, easily and at a glance. Among other things, it serves to monitor the operating windows and signals whether all settings have been made correctly. The segments of the signal lamp can be configured so that one machine lamp meets a wide range of requirements.

Summary

Format adjustment involves changing guide rails, sidebands or link chains due to a new format. This can be semi-automated or fully automated on the machines. It requires displacement measuring systems whose sensors provide feedback on the respective position.

If format parts on the machine have to be replaced, it must be ensured that the correct changeable part is installed at the correct position in the machine. Industrial identification systems such as RFID are suitable for this purpose. Each changeable part is equipped with a tag and, with the help of the read/write heads, it recognizes whether the correct changeable part is installed in the correct place.

Both automation options offer the following advantages:

  • Short set-up times and increased system productivity
  • Efficient error prevention
  • Increased machine flexibility
  • Avoidance of machine damage due to wrong parts when starting up the machine
  • Simple visualization for the operator

To learn more about format change visit www.balluff.com.