level of silo HMI

[robert_]

Can I use a touch panel like magelis (schneider electric) or Panel View (AB) with a stand alone PLC to monitor the level of a silo in real time or would have to be a SCADA system?

[DanW]

1) Something needs to measure the silo level. Top mounted radar? top mounted ultrasonic? Radar on a rope (TDR)? Load cells on the ground? motorized plumb bob? 2) The level measurement value has to be available as a signal 4-20mA? Modbus? Profibus? 3) I'm not sure what 'real time' has to do with it. The lag between making the measurement and getting a signal to a display is irrelevant on a silo that might have, maybe, a 1m/min maximum level change. The distinction must be with respect to retrieving the value from a data base historian after the fact. That's archival data. 4) When the measurement signal is 4-20mA, some people use a wall mounted digital indicator to display the level right at the silo in real time, as the measurement is made. A loop powered digital display is used when there's no local power to power the display. 5) Precision Digital has an indicator that operates as a Modbus master and can get data from a Modbus level transmitter and display the data in quasi-real time, maybe 1 second after the measurement is made. 6) Touch panels deal in digital protocols, Modbus, Ethernet/IP. Touch panels do not have I/O and are not 4-20mA compatible. To use a touch panel, the level measurement needs to be sent to a PLC and the touch panel needs to get it from the PLC (or the PLC sends it to the touch panel).

[Joe E.]

Red Lion's Graphite panels can control I/O: http://www.redlion.net/hmi-operator-panels/graphite-series I've never used them, but they look solid.

[Emperor]

Hi Robert, I have used ICP DAS USA product in the past for same purpose. They have some TouchPads also used as a PLC which is built in. You can check the link: http://www.icpdas-usa.com/touch_pad_controller.html?page=2 Thank you,