Communications with the Host

Section 1-4

The NT631/NT631C also supports OMRON’s high-speed 1:N NT Link that provides faster 1:N communications. The only PLCs that support the high- speed 1:N NT Link are CS1G/CS1H PLCs of version -EV1 and higher, CS1D PLCs, and CJ1G/CJ1H/CJ1M PLCs.

In the following sections, the term NT Link is used to refer to the NT Link com- munications method in general, the term 1:1 NT Link is used to refer specifi- cally to NT Links with a 1:1 connection, and the term 1:N NT Link is used to refer to both standard and high speed NT Links with 1:N connections. When necessary, the standard 1:N NT Link is distinguished from the high-speed 1:N NT Link.

Features of the NT Link The NT link has the following features.

High-speed communications with specific types of PLCs can be executed. The NT631/NT631C also supports OMRON’s high-speed 1:N NT Link.

Writing in units of bits to the PLC memory area is possible.

This enables the other bits of words to which a touch switch has been al- located to be allocated for other purposes (e.g. a lamp).

However, since data is written to the DM area in word units, the other bits of words allocated to touch switches in this area cannot be used for other purposes.

The NT link can be used even when the PLC is in the RUN mode. (When the host link method is used, the NT631/NT631C switches to the monitor mode when the PLC is in the RUN mode.)

In the case of PTs that support the standard 1:N NT Link (NT20S, NT31, NT31C, NT600S, NT620S, NT620C, NT625C, NT631, NT631C) up to 8 PTs can be connected to one port of the PLC and used at the same time. Up to 8 PTs (NT31, NT31C, NT631, and NT631C) can also be connected simultaneously when the high-speed 1:N NT Link is being used.

All of the PTs connected to a PLC port must use either the standard or high-speed 1:N NT Link; the two communications systems cannot share a single port.

When using a C200HX/HG/HE(-Z)E PLC and standard 1:N NT Links, up to three 1:N NT Link systems (i.e., 24 PTs) can be connected by installing a Communications Board in the option slot of the CPU Unit. (Only the standard 1:N NT Link can be used.) For details on the Communications Board, refer to the SYSMAC Communications Board Operation Manual (W304-E1-@).

When using a CQM1H PLC and standard 1:N NT Links, multiple 1:N NT Link systems can be connected by installing Serial Communications Boards in the Inner Board slots. For details on the Serial Communications Board, refer to the CQM1H Serial Communications Board Operation Man- ual (W365-E1-@).

Multiple 1:N NT Link systems (standard or high-speed) can be connected by installing a Communications Board in the Inner Board slot of the CPU Unit for a CS1G/H/D PLC or installing a Serial Communications Unit on the Backplane for a CS1G/H/D or a CJ1G/M/H PLC. For details on the Communications Board/Communications Unit, refer to the CS/CJ-series Serial Communications Board/Unit Operation Manual (W336-E1-@).

If the PLC supports the Programming Console function, the NT631/ NT631C can be used as a Programming Console.

If the PLC supports the Device Monitor function, the NT631/NT631C can be used to change the PLC’s operating mode and read/change data in the PLC’s memory areas.

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Omron NT631C manual Section