A Safety Relay or a Safety PLC: Where the Crossover Actually Is
Count the safety functions before you pick the box. Where a 440R relay wins, where a 440C-CR30 takes over, and what a safety network adds to the job.
Count the safety functions before you pick the box. Where a 440R relay wins, where a 440C-CR30 takes over, and what a safety network adds to the job.
The station is an IM 155-6 PN with an ET 200SP F-DI 8x24VDC HF in slot 3, the CPU is a 1515F-2 PN on TIA Portal V17, and the hardware compiles clean with a warning that says the F-module has no valid PROFIsafe address yet. The guard door on channel 2 is wired as two … Read more
A CPU 1515F-2 PN on TIA Portal V17, an ET 200SP station with an F-DI 8x24VDC HF, and channel 2 on it is a guard door. The buffer showed “Channel 2: Short-circuit” last week and the channel passivated; the electrician found a chafed wire in the door loom and repaired it, the buffer now says … Read more
The 1791ES-IB8XOBV4 on the palletiser cell failed on a Sunday, the spare from stores has the same catalogue number and the same three address switches set to 21, and the yellow triangle over it in the I/O tree has not moved in forty minutes. The GuardLogix 5580 project has a safety signature, the module’s Safety … Read more
A project built for a CPU 1214C DC/DC/DC, no CPU in the building until Thursday, and an S7-1200 PLCSIM instance one toolbar button away. Press it, pick PLCSIM in the PG/PC interface dropdown instead of the wired NIC, and the download that would have gone to 192.168.0.1 over the bench cable goes to a powered-up … Read more
The CPU says V4.6 and the hardware catalog stops at V4.5. What a hardware support package does, how to install one offline, and when you need a newer TIA.
How to pick discrete and analog I/O, get sinking and sourcing right, set RPI and electronic keying, wire a 4-20 mA loop and scale the raw counts.