Commreqs That Can Be Pending While Others Execute; Initialize Port Function (4300) - GE VersaMax PLC User Manual

Currently--
Autodial
pending
(4400)
COMMREQs
Write bytes
No
(4401)
Read bytes
No
(4402)
Read String
No
(4403)
Serial I/O / SNP / RTU Protocols
For public disclosure
12.4.3 COMMREQs that Can be Pending While
Others Execute
The table below shows whether Write Bytes, Read Bytes and Read String COMMREQs
can be pending when other COMMREQs are executed.
Set Up
Write Initialize
Input
bytes Port
Buffer
(4401) (4300)
(4301)
No Yes Yes
Yes Yes No
Yes Yes No

12.4.4 Initialize Port Function (4300)

This function causes a reset command to be sent to the specified port. It also cancels any
COMMREQ currently in progress and flushes the internal input buffer. RTS is set to
inactive.
12.4.4.1 Example Command Block for the Initialize Port
Function
address
address +1
address +2
address +3
address +4
address +5
address +6
12.4.4.2 Operating Notes
Note COMMREQs that are cancelled due to this command executing do not have their
respective COMMREQ status words updated.
NEW COMMREQ
Flush Read Write
Input port port
buffer status control
(4302) (4303) (4304
Yes Yes Yes
No Yes Yes
No Yes Yes
VALUE VALUE
(decimal) (hexadecimal)
0001 0001
0000 0000
0008 0008
0000 0000
0000 0000
0000 0000
4300 10CC
Read Read Cancel
bytes String Operation
(4402) (4403) (4399)
Yes Yes Yes
No No Yes
No No Yes
MEANING
Data block length
NOWAIT mode
Status word memory type (%R)
Status word address minus 1
(%R0001)
Not used
Not used
Initialize port command
GFK-1503E User Manual 237
Serial
Port
Setup
(FFF0)
No
No
No