Autonomous system, local display on the panel door (b)

When operating the system from the outside of the panel door, the operator needs no qualification for work inside of the panel. The plant is operated with panel door closed. The PLC may have no display, comapct types are usually used (IMIO105, ICIO205, markMX). The terminal is connected using a cross Ethernet cable. However, mostly an active network element (industrial switch) is used, so that a service PC can be connected to the HT102 terminal and the PLC. A single terminal is able to operate up to 4 PLCs. The terminal may be also located outside of the panel, being connected to the PLC over the technological network.

It is also possible to use a panel-mounted PLC (mark125) and attach the I/O modules over  the RS485 bus. Do not exceed the maximum datapoint amount that a PLC is able to host. Unlike with the HT102 solution, there are only variables from this PLC available on its display.


Two topologies with an LCD panel on the cabinet, left: HT102 terminal, right: PLC, mark125

Specification (topology on the left):

HT102             terminal for Merbon PLCs
markMX          compact PLC, 88 I/O
ICIO205          more PLCs if necessary

Specification (topology on the right):

mark125          Merbon PLC
RCIO               I/O module, 30 I/O
R…                  more I/O modules if necessary