4

Retrieving Detailed Status on the Channel

As discussed before, there are several forms of status available to the ladder program. These are all discussed in Section 4. One form of status is obtained through the Retrieve Detailed Channel Status (RDCS) command described later in this section.

Specifying the Location of the Channel Status

The Assign Channel Status Vector (ACSV) command tells the Ethernet Interface what the PLC reference table memory location will be used for the 64-bit Channel Status bits.

This Channel Command is required for users who have configured the Ethernet Interface using MMS-ETHERNET configuration mode with Logicmaster 90-70. If Logicmaster

90-70 configuration software has been used to configure the client Ethernet Interface in TCP/IP configuration mode, this Channel Command must not be used.

Note

Using TCP/IP configuration mode requires both Logicmaster 90-70 release 6.02 (or later) and Series 90-70 CPU firmware release 5.03 (or later).

If TCP/IP configuration mode has been used, then Logicmaster 90-70 has already specified an 80-bit area to hold the sixteen LAN Interface Status (LIS) bits and the sixty-four Channel Status bits. In this case, the PLC CPU will update these 80 bits once each scan with the latest data from the Ethernet Interface. Attempting to specify an additional 64-bit area would mean that the PLC CPU would update the Logicmaster-specified 80-bit area and the Ethernet Interface would update the user-specified 64-bit area. This would be wasteful in addition to slowing down overall PLC system performance. If possible, GE Fanuc recommends using TCP/IP configuration mode when using the TCP client capability of this Ethernet Interface.

If MMS-ETHERNET configuration mode must be used (such as when using a CPU 780, which will never be updated to firmware level 5.03 or later), then this Channel Command is the only way you may specify the location of the sixty-four Channel Status bits to the Ethernet Interface. Note that in MMS-ETHERNET configuration mode, Logicmaster 90-70 still specifies the location of the sixteen LIS bits.

4-10

TCP/IP Ethernet Communications User's Manual ± January 1996

GFK-1004B

Page 98
Image 98
GE GFK-1004B user manual Retrieving Detailed Status on the Channel, Specifying the Location of the Channel Status