Advertisement
12
GFK-2332X
Subject
COMMREQ Status Word value
of 0x54A0 occasionally
returned for EGD commands
Modbus/TCP channel aborted
during power-cycle
Controller response timeout
errors (8/08) in Ethernet
exception log under extremely
heavy SRTP traffic
SRTP channel transfers may
take up to 20 seconds after
power cycle
"rmdir" Station Manager
command does not work for
multi-level directory path
Intermittent Ethernet log event
8H/15H after power cycle
Intermittent Modbus/TCP
Server log events when using
"killms" Station Manager
command
Module intermittently
unresponsive after reset
A890 Commreq status after
multiple Modbus open
command attempts
Modbus/TCP request packets
RX3i Ethernet Interface Module IC695ETM001-HW IPI
Restrictions and Open Issues
Occasionally a COMMREQ Status Word value of 0x54A0 is returned after
COMMREQs for Ethernet Global Data commands when the previously-
transferred command has experienced retries in the network. Executing
the COMMREQ again results in successful transfer of the command.
After powering up an RX3i running Modbus/TCP client channels, the
establish connection occasionally fails because the server rejects the
"open" request from the client. The connection will then succeed if the
application retries the open when it sees a 0x9690 or 0xAA90 response to
an open request or to the first write request.
Under extremely heavy SRTP traffic conditions, the Ethernet Interface may
log an event in the Ethernet exception log (Event 8, Entry 2 = 08H)
indicating an overload condition. This error terminates the SRTP
connection. If this event appears, either the traffic load should be
reduced, or the application should use an alternate communications
method to verify that critical data transfers were not lost due to the
overload.
When SRTP communications are interrupted by a power cycle, the
Ethernet interface may require up to 20 seconds to reestablish TCP
connection used for SRTP communications.
The "rmdir" Station Manager command does not operate properly with a
multi-level directory path. Instead, first change to the parent directory,
then delete the target directory without specifying a path. For example,
the "rmdir dir1/dir2" results in "RMDIR Failed, dir1/dir2 does not exist".
Instead, first do "cd dir1" and then "rmdir dir2".
When starting after a power cycle, the Ethernet Interface may
intermittently log an exception (entry 8H, Entry 2 = 15H, Entry 3 = 0000H,
Entry 4 = 00aaH). This exception is benign and may be ignored.
When using the "killms" Station Manager command to manually terminate
an active Modbus/TCP server connection, the following Modbus/TCP errors
may occur in the Ethernet exception log: Event 2fH, Entry 2 = 209H, 212H,
21bH, or 221H. These errors may be ignored.
Intermittently, when the module is restarted by using the pushbutton or
Station Manager command, the module will blink its OK LED for 5
minutes before completing the restart. After the restart is complete the
module fails to communicate with the CPU module. The remedy is to
power-cycle the PLC.
When using a Commreq to open a Modbus/TCP Channel to a remote
server, if the initial Commreq returned an AA90 status, then future Open
Commands may return A890 status. This indicates that local networking
resources have been consumed and are not available for further
connection attempts. If this occurs, the application must wait at least
60 seconds before making the next connection attempt. This will allow
networking resources to be released and made available for the next
Modbus Open Command.
The Modbus/TCP server expects to receive each Modbus/TCP request in
a separate TCP packet. If multiple requests are sent in a single packet,
the server may or may not send a response to each request. If
responses are sent to the client, they will be sent in separate TCP
packets.
Description
March 2016
Advertisement
