18
WIRING cont.
Programming Considerations for the Output Board
Programming for the outputs is done in column r. If your unit is a totalizer
and
does
not contain the optional output board, your unit will not have column r in the pro-
gram mode, and you can skip this page and go on to the RS 485 communication
wiring. All of you that have either a totalizer with the output board option, or a batcher,
stick around.
OK, now that those guys are gone, we can talk behind their backs. And what were
going to talk about is outputs. Output boards come in two varieties: a dual relay and
a single relay/single transistor. Check the part number on your unit and compare it to
the model selection table on page 2 to determine which flavor you have. Output 1 is
always a relay, and is connected to terminals 1, 2, and 3. Output 2 is either a relay
connected to terminals 4, 5, and 6, or it is an optically isolated transistor connected
to terminals 5 and 6. The transistor output is generally used for the totalizer pulsed
output if that function is required. Relays are normally used for all other output
functions.
In the batcher, output 1 is not programmable. It is dedicated as the batch final relay.
It turns ON when the unit receives a start input, and turns OFF when the batch final
setpoint is reached, or when a stop input is received. Output 2 in the batcher and
both outputs in the totalizer are programmable. When dealing with these outputs,
there are two things to consider: when to turn ON, and when to turn OFF.
Turning ON will always be determined by an event appropriate to the function that
they are programmed to do. For the totalizer, there are three events that can cause an
output to turn ON:
1. When the totalizer count reaches the totalizer setpoint value (total setpoint).
2. When the flow rate crosses a setpoint value (rate low, rate high, rate low or
high).
3. Each time a unit of flow is counted (totalizer pulsed output).
Output 2 in the batcher may also turn ON at any one of these events, or may turn ON
at one of two others. They are a start input (prewarn setpoint) and when the cycle
count reaches a setpoint value (cycle setpoint).
Turning OFF will either be determined by an event or by timing. There are four
possibilities. Totalizer pulsed outputs are
pulsed
and turn OFF either after 500 +/- 84
m
sec (pulse fast), or 2
m
sec (pulse medium), or 10
m
sec (pulse slow). Totalizer
setpoint, rate setpoint, and cycle setpoint outputs may be timed or latched.
Timed
outputs allow the installer to program an ON time in the range of 0.01 to 99.99
seconds. When this time elapses, the output(s) turn OFF.
Latched
outputs turn off
when an unlatch event occurs. This event can be a start, stop, or reset input, or a
control input programmed as unlatch. Rate setpoint outputs will turn OFF when the
rate drops below a rate high setpoint, or goes above a rate low setpoint if the output
is in the
follows
mode.
