Addressing Reference
1785 PLC-5
19
Figure 18
Block-transfer Control Structure
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
EN
ST
DN
Reserved
RLEN – Requested Word Count (–32,768 thru +32,767)
DLEN – Transmitted Word Count (–32,768 thru +32,767)
ER
CO EW
FILE – File-type Number (–32,768 thru +32,767)
ELEM – Word Number (–32,768 thru +32,767)
I/O Rack
NR TO RW
slot
I/O Group
not
used
Table L
Example Block-transfer Control Addresses
To Address:
PLC Data Type:
Example Address:
Whole B-T Control
Structure
structure
$BT10:0
Requested-word Count
signed word
$BT10:0.RLEN
Transmitted-word Count
signed word
$BT10:0.DLEN
File-type Number
signed word
$BT10:0.FILE
Word Number
signed word
$BT10:0.ELEM
Rack/Group/Slot
signed word
$BT10:0.RGS
Done Bit
bit
$BT10:0.DN
Table M
ASCII String Mnemonics
Mnemonic
Structure Member
Size
PLC Data Type
.LEN
Length
2 bytes
signed word
Figure 19
ASCII String Structure
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
LEN – Length specifies an even number of bytes (2 – 82)
A maximum of 82 bytes of data accessible only by addressing the whole structure.