Status data, Types of status data – FANUC Robotics America GFK-1541B User Manual
Page 135
ries 90™ PLC User's Manual
–
May 2002
GFK-1541B
4
Status Data
This section describes all the status data that is available to the ladder program to determine the
state of the Ethernet Interface and its Modbus/TCP channels.
Types of Status Data
There are three main types of status data available to your ladder program:
1.
FT Output of the COMMREQ Function Block.
This output is set if there is a programming
error in the COMMREQ Function Block itself, if the rack and slot specified in the
COMMREQ SYSID parameter is not configured to contain an Ethernet Interface, or if the
data block length specified in the Command Block is out of range. This output also may
indicate that no more COMMREQ functions can be initiated in the ladder program until the
Ethernet Interface has time to process some of the pending COMMREQ functions.
If the FT Output is set, the CPU does not transfer the Command Block to the Ethernet
Interface. In this case, the other status indicators are not updated for this COMMREQ.
2.
Status Bits.
The status bits are updated in the CPU once each PLC scan by the Ethernet
Interface. These bits are generally used to prevent initiation of a COMMREQ function when
certain errors occur or to signal a problem on an established channel. The status bits include
the LAN Interface Status bits and the Channel Status bits. The starting location of these bits
is user-configurable and is set in harware config when the module is configured.
The LAN Interface Status bits monitor the health of the Ethernet Interface itself, such as the
LAN Interface OK bit and the AAUI Fuse Blown bit. The Channel Status bits monitor the
health of a channel.
3.
Communications Status Word.
The COMMREQ Status word (CRS word) provides
detailed information on the status of the COMMREQ request. The communications status
word is not updated in the CPU each scan as are the status bits. They are generally used to
determine the cause of a communication error after the COMMREQ function is initiated.
The cause is reported in the form of an error code described later in this section.The
COMMREQ Status word (CRS word) is returned from the Ethernet Interface to the PLC
CPU immediately if the Command Block contains a syntax error or if the command is local.
The location of the CRS word is defined in the Command Block for the COMMREQ
function.
The document is for study only,if tort to your rights,please inform us,we will delete