4 |
Establish Write Channel (2004)
The Establish Write Channel command requests that a channel be connected to a remote PLC and that data from the local PLC be transferred (periodically) to the remote PLC. The Command Block specifies the period, the number of writes to the server to perform, and the timeout allowed in waiting for each transfer to complete. The first write is performed immediately, regardless of the period specified.
Example Command Block
Establish a write channel (channel 6) to a remote PLC at IP address 3.0.0.1. Return the COMMREQ Status word to %R10. Write local PLC registers
The term local PLC is used here to identify the
The term remotePLC is used here to identify the
| Dec | (Hex) |
|
Word 1 | 00017 | (0011) | Length of Channel Command Data Block (17 - 25 words) |
Word 2 | 00000 | (0000) | Always 0 |
Word 3 | 00008 | (0008) | Memory type of CRS word (%R) |
Word 4 | 00009 | (0009) | CRS word address minus 1 (%R10) * |
Word 5 | 00000 | (0000) | Reserved |
Word 6 | 00000 | (0000) | Reserved |
Word 7 | 02004 | (07d4) | Establish Write Channel Command number |
Word 8 | 00006 | (0006) | Channel number (6) |
Word 9 | 00000 | (0000) | Number of write repetitions (write indefinitely) |
Word 10 | 00003 | (0003) | Time units for write period (3=seconds) |
Word 11 | 00007 | (0007) | Number of time units for write period (every 7 seconds) |
Word 12 | 00050 | (0032) | Timeout for each write (500 ms) |
Word 13 | 00008 | (0008) | Local PLC - memory type from which to write data (%R) |
Word 14 | 00050 | (0032) | Local PLC - starting address from which to write data (%R50) |
Word 15 | 00008 | (0008) | Remote PLC - memory type at which to store data (%R) |
Word 16 | 00100 | (0064) | Remote PLC - starting address at which to store data (%R50) |
Word 17 | 00008 | (0008) | Remote PLC - number of memory units (8 registers) |
Word 18 | 00001 | (0001) | Remote PLC - PLC (node) address type (IP address) |
Word 19 | 00004 | (0004) | Remote PLC - PLC (node) address length in words (4) |
Word 20 | 00003 | (0003) | Remote PLC - register 1 of IP address (3) |
Word 21 | 00000 | (0000) | Remote PLC - register 2 of IP address (0) |
Word 22 | 00000 | (0000) | Remote PLC - register 3 of IP address (0) |
Word 23 | 00001 | (0001) | Remote PLC - register 4 of IP address (1) |
Word 24 - 27 |
|
| Remote PLC - Program Name (needed for access to remote %P |
|
|
| or %L) (zero terminated and padded) |
Word 28 - 31 |
|
| Remote PLC - Program Block (needed for access to remote %L) |
|
|
| (zero terminated and padded) |
*Word 4 (CRS word address) is the only
(Word 7) Channel Command Number: Word 7 requests that a write channel be set up. If the command is processed successfully, it will result in attempting the specified number of transfers from the client to the server.
Chapter 4 Programming Communications Requests |
