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Contents
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PACSystems* RX7i & RX3i CPU Reference Manual
GFK-2222W
6.2
Serial I/O Protocol .................................................................................................................... 141
6.2.1
Calling Serial I/O COMMREQs from the CPU Sweep ........................................................................................ 141
6.2.2
Compatibility ........................................................................................................................................................................ 141
6.2.3
Status Word for Serial I/O COMMREQs ................................................................................................................... 141
6.2.4
Serial I/O COMMREQ Commands .............................................................................................................................. 143
6.2.5
Overlapping COMMREQs ................................................................................................................................................ 144
6.2.6
Initialize Port Function (4300) ...................................................................................................................................... 145
6.2.7
Set Up Input Buffer Function (4301) ......................................................................................................................... 146
6.2.8
Flush Input Buffer Function (4302) ............................................................................................................................ 147
6.2.9
Read Port Status Function (4303) .............................................................................................................................. 148
6.2.10
Write Port Control Function (4304) ........................................................................................................................... 150
6.2.11
Cancel COMMREQ Function (4399) ........................................................................................................................... 151
6.2.12
Autodial Function (4400) ................................................................................................................................................ 152
6.2.13
Write Bytes Function (4401) ......................................................................................................................................... 154
6.2.14
Read Bytes Function (4402) .......................................................................................................................................... 155
6.2.15
Read String Function (4403) ......................................................................................................................................... 157
6.3
RTU Slave Protocol ................................................................................................................... 159
6.3.1
Message Format ................................................................................................................................................................. 160
6.3.2
Cyclic Redundancy Check (CRC) ................................................................................................................................. 165
6.3.3
RTU Message Descriptions ........................................................................................................................................... 169
6.3.4
RTU Scratch Pad ................................................................................................................................................................. 185
6.3.5
Communication Errors .................................................................................................................................................... 186
6.3.6
RTU Slave/SNP Slave Operation with Programmer Attached .................................................................... 189
6.4
SNP Slave Protocol ................................................................................................................... 190
6.4.1
Permanent Datagrams ................................................................................................................................................... 190
6.4.2
Communication Requests (COMMREQs) for SNP .............................................................................................. 190
Appendix A Performance Data ................................................................................................................... 191
A-1 Boolean Execution Times ..................................................................................................................... 192
A-1.1
Boolean Execution Measurements (ms per 1000 Boolean executions) ................................................ 192
A-2 Instruction Timing ................................................................................................................................. 193
A-2.1
Overview ................................................................................................................................................................................. 193
A-2.2
CPU Version Information ................................................................................................................................................ 194
A-2.3
RX3i Instruction Times ..................................................................................................................................................... 195
A-2.4
RX7i Instruction Times ..................................................................................................................................................... 208
A-3 Overhead Sweep Impact Times .......................................................................................................... 219
A-3.1
Base Sweep Times ............................................................................................................................................................. 220
A-3.2
What the Sweep Impact Tables Contain ............................................................................................................... 222
A-3.3
Programmer Sweep Impact Times ........................................................................................................................... 223
A-3.4
I/O Scan and I/O Fault Sweep Impact..................................................................................................................... 224
A-3.5
Ethernet Global Data Sweep Impact ....................................................................................................................... 231
A-3.6
EGD Sweep Impact for Embedded Ethernet Interface on RX3i CPE305 and CPE310 ................... 234