GE PACSystems RX7i, User Manual

Page: 99 / 276

Chapter 5. Ethernet Global Data
86 PACSystems* RX7i & RX3i TCP/IP Ethernet Communications User Manual GFK-2224Q
COMMREQ Status Word Values
The following table lists the CRS values returned by the SNTP Time Transfer commands. For a discussion of CRS
major and minor codes, refer to “Communication Request” in the
PACSystems CPU Reference Manual,
GFK-
2222.
Before executing a COMMREQ, the application logic should set the CRS word to 0. After executing a COMMREQ,
the application logic should monitor the CRS word to determine the completion and success of that command.
Minor
(Hex)
Major
(Hex)
Description
00 01 Successful completion.
04 01 Successful completion. The Ethernet interface is not locked to an SNTP server at this
time, so the CPU clock was not updated.
05 01 Successful completion. The CPU clock was already synchronized to the SNTP server
via this Ethernet interface, so the CPU clock was not updated again.
11 0C Internal error reading clock status or stratum value from this Ethernet interface. The
clock status/stratum values were not returned.
12 0C Internal error enabling CPU time synchronization. The CPU clock will not be
synchronized to an SNTP server at this Ethernet interface.
13 0C Internal error disabling CPU time synchronization.
07 0D COMMREQ data block length (COMMREQ word 1) is too short.
08 0D COMMREQ command code (COMMREQ word 7) is not recognized.
10 0D CPU and/or ENET firmware version does not support SNTP Time Transfer feature.
12 0D Attempted to enable CPU time sync on this Ethernet interface while already enabled
on another Ethernet interface. The logic application must first disable CPU time sync
on the original Ethernet interface before enabling on another Ethernet interface.
13 0D Attempted to disable CPU time sync that was not previously enabled at this Ethernet
interface.
14 0D Invalid COMMREQ command data.
15 0D COMMREQ not allowed because SNTP Time Transfer feature was not configured.
16 0D COMMREQ data block length (COMMREQ word 1) is too long.
SNTP Operation
In an SNTP system, a computer on the network (called an SNTP server) sends out a periodic timing message to
all of the SNTP-capable Ethernet Interfaces on the network, which keep their internal clocks synchronized with
this SNTP timing message.
In a redundancy system, SNTP operation is unaffected by the current Ethernet redundancy state or by
redundancy role switches.
SNTP server dates before January 1, 1989 are not supported.
Normal SNTP Operation
If SNTP is configured, the default mode of operation is Broadcast and Multicast. For Unicast mode of
communication, you will need to configure the necessary parameters as defined in Appendix A, “Configuring
Advanced User Parameters.”