Most Press Brake machines operate in a similar manner - a Ram moves downwards to bend pieces of metal. Collecting signals for machine utilization is therefore fairly simple, let's take a look!
Please Note: This article is part of the Digital I/O Integration process. For more details on the process as a whole, please review the Digital I/O Integration Guide
Ram Down Signal
The most common method of monitoring utilization from a Press Brake is by capturing the "Ram Down" signal. Capturing this signal from the machine is the most common way of determining utilization from a press brake because the movement of the ram indicates that the machine is being used. By capturing this signal, MachineMetrics can tell whether the machine is idle, or actively bending parts.
Whenever the Ram moves downwards, an electrical signal is fired to actuate a solenoid. This electrical signal is what you need to locate within the electrical cabinet.
Please Note: The I/O module is capable of receiving DC voltage NO HIGHER than 40VDC. If the signal from your machine is high AC voltage, a relay must be used to transfer the signal to the I/O Module.
Relay, Contactor, PLC Output
In many cases, the signal for Ram Down can be collected from either a relay, contactor, or PLC output. We recommend searching through the electrical schematics for this signal and associated components.
Pictured below is an electrical schematic that shows terminal V47 of block X8 as an output for the Ram "Down" - This output is energized with 24VDC when the Ram moves downwards. Connect a wire from this output directly to AIN0 of the I/O Module:
Pictured below is an electro-mechanical relay that fires a solenoid associated with the machine's Ram. Output terminal 6 is energized with 24VDC when the Ram moves downwards, so you can connect a wire directly from terminal 6 to AIN0 of the I/O Module.
Often the ram is only actuated by a footswitch. If this is the case for your machine, the easiest method of collecting the Ram Down signal would be to locate the footswitch in the electrical schematics.
In the schematic below, terminal 68 has been identified as a 24VDC output whenever the footswitch is actuated. If the Ram is operated solely by the footswitch, a wire can be connected from terminal 68 directly to AIN0 of the I/O Module.
In the image below you can see the machine is equipped with two footswitches. If the Ram of your machine is operated solely by more than one footswitch, you should collect the signal from each.
It is possible that your press does not have a "Ram Down" signal - please note that you are not limited to the signal that indicates the ram is moving downwards. Certain machines have outputs for "Bend Complete", or "Ram Up" would work similarly. If your Press Brake has a signal that would indicate the machine is in use, it can be used by MachineMetrics.
To learn more about Adapter Scripts, see this article.
The Adapter Script for this type of integration is utilization only. The Ram Down signal will turn on & off periodically throughout a cycle. The signal will have a "saw-tooth" appearance, as pictured below.
In order to prevent periods of idle time between Ram Down signals, an "off-delay" should be added to the Adapter Script. This will prevent the machine from showing idle between every stroke of the Ram. The machine will show idle after the Ram Down signal has not been seen for the duration of the off-delay. Pictured below is an example of a utilization only Adapter Script with an off-delay:
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