Watson-Marlow 520Du User Manual

Page 79

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Watson-Marlow 520Du User Manual

79

24.1 RS232 and RS485 command strings

Command

Parameters

Meaning

nCA

-

Clear LCD display

nCH

-

Home the cursor

nDO

xxxxxxxxxx
<,yyyyy>

Set and run one dose of xxxxxxxxxx tacho
pulses, with optional drip of yyyyy (maxi-
mum 11,000) tacho pulses. See note 1

nTC

-

Clear the cumulative tachometer count

nSP

xxx.x

Set speed to xxx.x rpm

nSI

-

Increment speed by 1rpm

nSD

-

Decrement speed by 1rpm

nGO

-

Start running

nST

-

Stop running

nRC

-

Change direction

nRR

-

Set direction to clockwise

nRL

-

Set direction to counter-clockwise

nRS

-

Return status. See note 2

nRT

-

Return the cumulative tachometer count

nW

[line 1]~[line 2]~
[line 3]~[line 4]@

Display text on 1 to 4 lines with ~ as the
line delimiter. Terminated by the @ charac-
ter. See note 3

nZY

-

Return 0 for stopped or 1 for running

Note 1: The correlation between tachometer pulses and motor rotation is fixed
and provides a measurable and absolute way of monitoring the number of revo-
lutions of the gearbox output shaft - 10,982 pulses per revolution. This in turn
allows the count to be equated to the amount of material dispensed - assuming
that the pumphead type and tube size are known.

Note 2: The status is returned to the sender in the following format: [pump
type] [ml/rev] [pumphead] [tube size] [speed] [CW/CCW] P/N [pump number]
[tacho count] [0/1 (stopped/running)] !
For example: 520Du 15.84 520R 9.6MM 220.0 CW P/N 1 123456789 1 !

Note 3: If the pump speed is changed subsequently, the
pump must display the screen shown here (example fig-
ures only) for 4 seconds before reverting to the custom
display. 1 to 4 lines of text can be written with ~ as the
line delimiter and @ as the message end.
i.e., 1W520Du@ and 1W520Du~@ are both valid commands.

Note 4: In all cases ‘n’ can be any number from 1 to 16 inclusive, and by
exception the # symbol can be used as an all-drives command; but not with the
RS, RT or ZY commands, as the results would be indeterminate.

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