Rockwell Automation 1747-ASB Remote I/O Adapter - Manual (Page 130)

Publication 1747-UM006B-EN-P - June 2003
A-2 Specifications
Network Specifications
Baud Rate Determination of Maximum Cable Length and Terminating
Resistor.
Throughput is the time between when a control system senses an
input event on an I/O module in a 1747-ASB chassis to when an
output event occurs on an I/O module within the same 1747-ASB
chassis. There are three types of 1747-ASB module throughput:
Troughput Production
•
discrete throughput (time from discretely mapped input to
discretely mapped output) without block transfers present
•
discrete throughput (time from discretely mapped input to
discretely mapped output) with block transfers present
•
block transfer throughput (time from block transfer mapped
input to block transfer mapped output)
Discrete Throughput Overview
The 1747-ASB module system discrete throughput is comprised of:
•
the total PLC or SLC processor scan time
•
the total RIO link scan time
•
1747-ASB module backplane scan time
•
the scanner module output delay time (only if scanner is a
separate module from the processor, otherwise value is 0)
•
the scanner module input delay time (only if scanner is a
separate module from the processor, otherwise value is 0)
•
the input module delay time
•
the output module delay time
Table 8.1 Baud Rate Determination of Maximum Cable Length and Terminating
Resistor Size
Baud Rate Maximum Cable Distance
(Belden 9463) Resistor Size
Using Extended
Node Capability
57.6K baud 3048 meters (10,000 feet)
82
Ω
1/2 Watt 115.2K baud 1524 meters (5,000 feet)
230.4K baud 762 meters (2,500 feet)
Not Using
Extended Node
Capability
57.6K baud 3048 meters (10,000 feet)
150
Ω
1/2 Watt
115.2K baud 1524 meters (5,000 feet)
230.4K baud 762 meters (2,500 feet) 82
Ω
1/2 Watt