Bradley Smoker PLC-5 Average DH+ Link Response Time Test Results, Number of Controllers

9-16Communicating with Devices on a DH+ Link

Test Setup

One to 22 PLC-5 controllers were used with one personal computer online. Each PLC-5 controller executes 1K of ladder logic.

Initial testing was done with one PLC-5 controller writing data to another PLC-5 controller. The response time was recorded. Additional PLC-5 controllers were added to the network, each writing the same amount of data to a PLC-5 controller at the next highest station address. Four separate tests were run using data transmissions of 50, 100, 250, and 500 words.

Average DH+ Link Response Time Test Results

This section shows graphically the results of testing performed on a DH+ link where the number of stations and words sent in the message varies.

The figure below shows the average response time of messages of varying sizes on a DH+ link with a varying numbers of stations. It also gives you an idea of the typical response time you can expect on a given DH+ link.

	5.0																					X
	4.5
	4.0
	3.5														X
Response	3.0										X											+
Time	2.5
	2.0							X							+
(Sec)						X
	1.5				X						+
				X		+		+
	1.0		X		+
		X
	X			+
		+	+
	0.5+
	0.0
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22
										Number of Controllers
									Number of PLC-5 Processors

50 W

100 W

+250 W X 500 W

W=Words

Publication 1785-UM012D-EN-P - July 2005