Rockwell Automation 1785 PLC-5 User Manual download pdf (Page 153)

Reference Information

Appendix B

B-6

able B.B

Data

able T

ypical T

ransfer T

ime Using Method 2 Program

with Minimal Progam Scan (4–9 ms)

Number of Blocks

Being Transferred

Number of Words

Being Transferred

Transfer Time (in ms)

for Series A BCM

(see notes 1 & 2)

Transfer Time (in ms)

for Series B BCM

Fast Transfer Mode

Enabled (see notes 1,

3, & 4)

1 62 170–250 60–80

3 186 200–300 90–120

7 434 350–500 130–180

10 620 350–600 170–230

16 992 400–1000 180–260

32 1984 – 320–720

64 3968 – 700–1400

These times do not significantly change with program scan, but as the number of blocks increase

so does program scan.

Times were taken using a PLC-5/25 processor.

Series B BCM module with fast mode disabled is approximately 50% slower than the times

shown.

Times were taken using a PLC-5/40 processor with one channel configured for DH+ and three

channels configured for remote I/O scanner at 230 kbaud.

Program scan 12–16 ms.

Program scan 20–25 ms.

Program scan 30–35 ms.

General Considerations

Data table transfer time increases with the number of blocks in a data

segment. This is because the secondary 1785-BCM module must wait for

the last block to be transferred from the primary system before it can

release its first block for BTR by the secondary processor (normal

transfer).

In time-critical applications, you may use Fast Data Transfer mode (switch

2 of switch assembly SW1). In this case, the secondary processor does not

need to wait for the complete data segment in order to release its first block

for BTR by the secondary processor.

1 2 ... 148 149 150 151 152 153 154 155 156 157 158 159 160 161

Comments to this Manuals

No comments

Rockwell Automation 1785 PLC-5 User Manual Page 153

Comments to this Manuals

Related products and manuals for Recording Equipment Rockwell Automation 1785 PLC-5