Emerson PACSystems RX3i - Page 163

PACSystems™ RX3i and RSTi-EP CPU Reference Manual Section 6
GFK-2222AK October 2019
Serial I/O, SNP & RTU Protocols 155
6.2.13.1 Example Command Block for the Write Bytes Function
Value
(decimal)
Value
(hexadecimal)
Meaning
Address
0006
0006
Data block length (includes
characters to send)
Address +1
0000
0000
NOWAIT mode
Address +2
0008
0008
Status word memory type (%R)
Address +3
0000
0000
Status word address minus 1
(%R0001)
Address +4
0000
0000
Not used
Address +5
0000
0000
Not used
Address +6
4401
1131
Write bytes command
Address +7
0030
001E
Transmit time-out (30 seconds).
See note below.
Address +8
0005
0005
Number of bytes to write
Address +9
25960
6568
‘h’ (68h), ‘e’ (65h)
Address +10
27756
6C6C
‘l’ (6Ch), ‘l’ (6Ch)
Address +11
0111
006F
‘o’ (6Fh)
Although printable ASCII characters are used in this example, there is no restriction on the
values of the characters that can be transmitted.
6.2.13.2 Operating Notes
Specifying zero as the Transmit time-out sets the time-out value to the amount of time
actually needed to transmit the data, plus 4 seconds.
CAUTION
If an Initialize Port (4300) COMMEQ is sent or a Cancel Operation (4399) COMMREQ is
sent in either Cancel All or Cancel Write mode while this COMMREQ is transmitting a
string from a serial port, transmission is halted. The position within the string where the
transmission is halted is indeterminate. In addition, the final character received by the
device the CPU is sending to is also indeterminate.