GE RX3i

Chapter 6. Programming EGD Commands
106 PACSystems* RX7i & RX3i TCP/IP Ethernet Communications User Manual GFK-2224Q
(Word 20) Remote Server - Network Address Length: Word 20 specifies the length in words of the remote PLC
IP address in this COMMREQ Command Block. Word 20 must contain 4.
(Words 21 – 24) Remote Server - IP Address: Words 21–24 specify the four integers, one integer per word, of
the dotted-decimal IP address of the remote PLC to be accessed.
6.9 Masked Write to EGD Exchange (4004)
The Masked Write to EGD Exchange command can be used to write one or more bits in a single byte of a
configured Ethernet Global Data exchange in a remote producer node. EGD protocol prohibits writing to a
consumed exchange. This command can be sent to PACSystems PLCs and to other EGD Class 2 devices.
In a PACSystems PLC, writing an EGD exchange modifies the PLC reference memory locations configured to be
transferred at the specified offset in the exchange. Thus current process data will be updated, not the data that
was transferred last in the exchange.
Masked Write EGD Exchange Command Block
Word Offset
Value
Description
Word 1
Length of command data block
Always 17
Word 2
0
Always 0 (no-wait mode request)
Word 3
(See table on page 95)
Memory type of COMMREQ Status Word
Word 4
0-based
13
Offset of COMMREQ Status Word
Word 5
0
Reserved
Word 6
0
Reserved
Word 7
4004 (fa4H)
Masked Write to EGD Exchange command number.
Word 8
Retry time, in milliseconds
The time between retries of command transfers. Default is
1000ms.
Word 9
Bit mask, set bit to be written to 1,
rest to 0
The bit mask selects the individual bit to be written. The
most significant bytes of Word 9 and Word 10 are ignored.
Word 10
Write 0 or 1 to selected bit.
Value to set the bit selected by the bit mask in Word 9.
Word 11
Remote signature
EGD Exchange signature. This should be 0 for PLCs when
not using signatures. If run-mode store of EGD will be
used, the use of signatures is highly recommended.
Word 12
Remote Producer ID (least
significant word)
EGD Producer ID
Word 13
Remote Producer ID (most
significant word)
Word 14
Remote Exchange ID (least
significant word)
EGD Exchange ID
Word 15
Remote Exchange ID (most
significant word)
Word 16
Remote Exchange Offset
Byte offset (0-based) in the exchange that should be read.
Word 17
Network address type
Must be 1. Indicates an IP address will be used.
Word 18
Network address length
Must be 4 for IP address.
Group ID (multicast) is not permitted.
Word 19 to
Word 22
IP Address of the remote PLC
Four integers, specified as one integer per word of the
dotted-decimal IP address of the remote PLC. May not be
a group IP address.
Word 23
Reserved
Always 0.