This article provides steps attached in a pdf to turn off the 5553L and 6553L monitors remotely via serial connection

The 53-Series monitors have a 3.5 mm connector for an RS232 connection, as shown in the User Guide for each product, available from the Elo web site under the Resources heading on the product page.  A DB9 to 3.5 mm cable is included in the box to allow connection to a standard RS232 serial portThe virtual COM connectioin via the USB touch cable may also be used.  Many functions are available; consult the remote management documentation.