Omron C500-LK009-V1 User Manual

A maximum of two PC Link Units can be mounted to the same PC. If two PC
Link Units are mounted to one PC anywhere in the System, the System is
multilevel, and all Units must be set for a Multilevel System (see 4-2-2 Switch
Settings). In a Multilevel System, operating levels must be set to create PC
Link Subsystems. Each Subsystem will have its own polling unit.

Up to four Subsystems are possible. There will always be one more Subsys-
tem than there are PCs to which two PC Link Units are mounted. Only oper-
ating levels 0 and 1 are set, as it is necessary only to differentiate between
two PC Link Units on the same PC. All of the PC Link Unit in the same Sub-
system must be set to the same level.

A PC Link System with three Subsystems is shown below. Any one of the PC
Link Units in any Subsystem may be designated as the polling unit. All other
Units would be polled units. The small boxes shown connecting the PC Link
Units are Link Adapters, which are used to connect PC Link Units when more
than two are used in a Subsystem. See following sections for details on Sys-
tem design and Link Adapters. (The 3G2A5-LK003-E PC Link Unit cannot be
used in Multilevel Systems.)

PC Link Unit

Operating Levels and Polling

Section 1-2