WATLOW Series 988 User’s Manual 8.19
General Software Features, Chapter 8
General Software
Sample Application
An engineer has a machine with eight independent zones of heat. Hewants to change set points on all zones without having to adjust each con-trol individually. This can be achieved using a Series 988 with a 0-5VÎ(dc) retransmit output as the master controller. The seven remote 988swill use the 0-5VÎ(dc) signal on input 2 as a remote set point. When theset point is changed on the master controller, the retransmit outputchanges the set points of the seven remote controllers. By enabling theramp to set point feature in the master controller, all eight zones areramped up to set point at a user-defined rate on power up.The retransmit output from the master Series 988 is set so that 0VÎ(dc)represents 0°F and 5VÎ(dc) represents 800°F. On the remote controllers,set the input 2 DIP switch to the position for the 0-5, 1-5, 0-10VÎ(dc)process input. In the Input Menu, under the Input 2 prompt [`In2],select 0-5. The Remote Set Point prompt [`rsp] should be set to ON[``on] and decimal 2 [deC2] set to 0. The range low 2 [`rL2] and therange high 2 [`rH2] parameters will establish the scaling for the remoteset point input. Range low 2 [`rL2] should be set to 0 and range high 2[`rH2] should be set to 800. To operate a specific zone ten degrees hotterthan the others, increase the range low 2 [`rL2] to 10 and the range high2 [`rH2] to 810.With remote set point [`rSP] enabled and local [```L] selected under theLocal-remote prompt [`L-r] in the System Menu, the set point is adjustedusing the up-arrow and down-arrow keys. Selecting remote [```r] underthe Local-remote prompt [`L-r], disables the up-arrow and down-arrowkeys, allowing the set point value to be manipulated by the input 2 signal.
TLTL
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zone 1

Master

output 3

zone 2

Remote
input 2

zone 3

Remote
input 2

zone 4

Remote
input 2

zone 5

Remote
input 2

zone 6

Remote
input 2

zone 7

Remote
input 2

zone 8

Remote
input 2

Figure 8.19 -

Zone heating with

remote set point.

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