Convergent Water Controls DIGICHEM Plus + User manual

Instruction Manual
Instruction Manual for
Water Treatment Controller
Model: DIGICHEM®Plus+
(All software versions to 0.91)
Fill in serial
number here Ö
Refer to
back page
Supplied by:
Convergent Water Controls Pty Ltd
2/4 Huntley Street, PO Box 7058
Alexandria NSW 2015
t: [phone] w: cwc.com.au
f: [phone] e: [email protected]
M1 ver 4.0

Manufacturer: Convergent Water Controls Pty Ltd, Sydney Australia.
Note: On-going product development at Convergent Water Controls may lead
to changes in the specifications of this product.
Warranty: This product is guaranteed for a period of 12 months from installation
date or 18 months from Invoice date (whichever occurs first). The
warranty applies to manufacturing or component defects which may
cause the unit to malfunction under specified conditions. The guarantee
does not cover damage due to abuse, tampering or improper installation.
Disclaimer: Convergent Water Controls will not be held liable for any consequential
damage or loss arising resulting from product malfunction.

T
Ta ab bl le e o of f C Co on nt te en nt ts s
1. Introduction...........................................................................................................................5
2. Installation ............................................................................................................................6
2.1 Electrical Wiring...........................................................................................................................6
2.2 Conductivity Probe Installation & Maintenance...............................................................................8
3. Controller Functionality.........................................................................................................9
3.1 Menu Logic.................................................................................................................................. 9
3.2 Pushbuttons .............................................................................................................................. 10
3.3 Controller Display Information .................................................................................................... 11
3.4 Comms Port............................................................................................................................... 11
4. Commissioning.....................................................................................................................11
4.1 Start-Up .................................................................................................................................... 12
4.1.1 Start-Up Delay ...............................................................................................................................13
4.2 Setting Time & Date................................................................................................................... 14
4.3 Calibration................................................................................................................................. 14
4.3.1 Conductivity (TDS / µS) Calibration..................................................................................................15
4.3 2 ORP mV Calibration........................................................................................................................18
4.3 3 pH Calibration................................................................................................................................22
4.4 Testing Relay Outputs................................................................................................................ 24
4.5 Manual Dose.............................................................................................................................. 26
4.6 View Settings............................................................................................................................. 29
4.7 Factory Settings......................................................................................................................... 30
5. Programming Setup Menu...................................................................................................31
5.1 µS/TDS Setup............................................................................................................................ 31
5.1 1 Set Conductivity Units.....................................................................................................................32
5.1.2 Set Bleed Setpoint..........................................................................................................................32
5.1.3 Set Conductivity Hysteresis .............................................................................................................33
5.1.4 Set Conductivity Bleed Cycle............................................................................................................34
5.2 ORP Setup................................................................................................................................. 35
5.2.1 Enable / Disable ORP Control ..........................................................................................................36
5.2 2 Select ORP Operation .....................................................................................................................36
5.2.3 Set ORP Setpoint............................................................................................................................37
5.3 pH Setup................................................................................................................................... 37
5.3.1 Enable / Disable pH Control.............................................................................................................38
5.3.2 Select pH Operation........................................................................................................................38
5.3.3 Set pH Setpoint..............................................................................................................................39
5.4 pH and ORP Control Method Setup.............................................................................................. 39
5.4.1 Setting the Control Method .............................................................................................................40
5.4 2 On/Off Control...............................................................................................................................40
5.4.3 Proportional Control........................................................................................................................43
5.4.4 Explanation of pH Control Methods ..................................................................................................44
5.4.5 Explanation of ORP Control Methods................................................................................................45
5.5 Alarm Parameters ...................................................................................................................... 48
5.5.1 Conductivity Level Alarms ...............................................................................................................48
5.5.2 ORP Level Alarms...........................................................................................................................49
5.5.3 pH Level Alarms.............................................................................................................................50
5.5.4 No Flow Alarm ...............................................................................................................................52

5.5.5 Delay On Alarm..............................................................................................................................52
5.5.6 Bleed Timer Alarm..........................................................................................................................53
5.5.7 ORP Dose Timer Alarm ...................................................................................................................54
5.5.8 pH Dose Timer Alarm .....................................................................................................................55
5.5.9 Timer Alarm Hysteresis (Software ver 0.91 & later)...........................................................................56
5.5.10 Alarm Override (Software ver 0.80 & later).....................................................................................56
5.6 Inhibitor & Dispersant Setup....................................................................................................... 57
5.6.1 Dose on Bleed Mode.......................................................................................................................58
5.6.2 After Bleed Mode............................................................................................................................61
5.6.3 Twenty Four Hour Per Day (24hr/day) Cycle.....................................................................................62
5.6.4 Make-Up Water Pulses....................................................................................................................63
5.6.5 Bleed Water Pulses.........................................................................................................................65
5.7 Biocide Setup............................................................................................................................. 65
5.8 Pre-Bleed Setpoint ..................................................................................................................... 71
5.9 Bleed Lock-out Setpoint.............................................................................................................. 71
5.10 Condenser Pump Timer ............................................................................................................ 72
5.11 Flow Switch ............................................................................................................................. 74
5.12 Advanced Setup Menu.............................................................................................................. 76
5.12.1 Data Logging ...............................................................................................................................77
5.12.2 Disinfection..................................................................................................................................79
5.12.3 Extra Inhibitor Dose......................................................................................................................81
5.12.4 Water Volume Counters ................................................................................................................82
5.12.5 Cycles of Concentration.................................................................................................................84
5.12.6 Password Setup............................................................................................................................85
5.12.7 Controller Name...........................................................................................................................87
5.12.8 Site Name....................................................................................................................................87
5.12.9 Remote Communications...............................................................................................................88
5.12.10 LCD Contrast (Software ver 0.80 & later)......................................................................................89
6. Factory Settings...................................................................................................................90
7. Specifications.......................................................................................................................91
8. Maintenance Schedule.........................................................................................................92
9. Optional Extras ....................................................................................................................92
10. Service & Technical Support................................................................................................94

Page 5 of 95
1. Introduction
Primarily designed for cooling tower water treatment, the DIGICHEM Plus+
electronic controller incorporates the following key features:
•Conductivity bleed control
•pH Control
•ORP Control
•Dispersant pump dosing control
•Inhibitor pump dosing control
•Dual Biocide pump control (via 10 independent 28-day timer programs)
•On Board Data logging
•Tower circulating/condenser pump override facility with delay-off timer
•High and Low Conductivity, pH & ORP alarms with programmable trip delay
•Internet Connectivity

Page 6 of 95
2. Installation
Mount the DIGICHEM Plus+ on a flat vertical surface away from extreme heat,
humidity or areas where temperature variations are extreme, ideally at eye-
level to allow good visibility of the LCD display. Also ensure that a 240VAC
mains power point is located nearby.
Please refer to the detailed installation instructions for the system you have
ordered (supplied with system).
2.1 Electrical Wiring
CAUTION: If opening the controller, pull the lid away from the base slowly to
ensure you do not impose any strain on the interconnecting cable,
which easily unplugs from the motherboard.
The diagrams below show the connections to the DIGICHEM Plus+ controller
circuitry:
12345678910 11 12 13 14 15 16 17 18 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Upper Terminals
Lower Terminals
Input Terminals
55 56
GSM/GPRS PORT
I/O PORT
I/O PORT
PROCESSOR BOARD CONNECTOR Output Fuse - 4A
Controller Fuse - 2A

Page 7 of 95
Terminal
Number Description
1ORP Probe Signal ( White )
2ORP Probe Common ( Green )
3Ground Probe
4pH Probe Signal ( White )
5pH Probe Common ( Green )
6Conductivity Probe PR+ ( Red )
7Conductivity Probe PR- ( Yellow )
8Conductivity Probe CM+ ( Blue )
9Conductivity Probe Screen ( Grey )
10 Flow Switch
11 Flow Switch
12 Water Meter - Make Up
13 Water Meter - Make Up
14 Water Meter - Bleed
15 Water Meter - Bleed
16 Spare
17 Spare
18 Spare
Terminal
Number Description
37 Common Earth
38 Common Earth
39 Common Earth
40 Common Earth
41 Common Earth
42 Condenser Pump Common
43 Condenser Pump N/O (Volt-Free)
44 Auxiliary Output Neutral
45 Dispersant Output Neutral
46 pH Output Neutral
47 Biocide B Output Neutral
48 Biocide B Output Neutral
49 Biocide A Output Neutral
50 Inhibitor C Output Neutral
51 Solenoid Output Neutral
52 Mains Output Neutral
53 Mains Supply Neutral
54 Mains Earth
Terminal
Number Description
19 Common Earth
20 Common Earth
21 Common Earth
22 Common Earth
23 Common Earth
24 Alarm N/C (Volt-Free)
25 Alarm N/O (Volt-Free)
26 Alarm Common
27 Auxiliary Output Active (240VAC)
28 Dispersant Output Active (240VAC)
29 pH Output Active (240VAC)
30 Biocide B Output Active (240VAC)
31 Biocide B Output Active (240VAC)
32 Biocide A Output Active (240VAC)
33 Inhibitor C Output Active (240VAC)
34 Solenoid Output Active (240VAC)
35 Mains Output Active (240VAC)
36 Mains Supply Active (240VAC)
12345678 9 10 11 12 13 14 15 16 17 18 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Power Terminals
Input Terminals
Earth Terminals
Terminal
Number Description
55 Mains Output Active (240VAC)
56 Mains Output Neutral
55 56
Fuses: Controller fuse: 2A/250VAC (M205, 20mm x 5mm diameter)
Output fuse: 4A/250VAC (M205, 20mm x 5mm diameter)
Notes on Alarm Relay Contacts :
1. Alarm relay is energised (ie. 25 connected to 26) during normal
operation of the unit.
2. Alarm relay de-energises (ie. 24 connected to 26) when an alarm
condition is confirmed or when the unit loses power.
Notes on Flow Switch:
A flow switch with N/O or N/C volt-free contacts is required to be connected to
terminals 10 & 11 (not polarity sensitive). The flow switch logic is
programmable via the menu.
Notes on Water Meter Inputs:
Water meters with Volt-free pulse outputs (e.g. Reed switches) are required for
Make-Up & Bleed water meter inputs.
For Mag-flow water meters with opto-coupled outputs, use terminals 12 & 14
for the +, and terminals 13 & 15 for the – inputs from the water meter.
NOTE: Terminals 55 & 56 may be omitted.

Page 8 of 95
2.2 Conductivity Probe Installation & Maintenance
The probe is supplied screwed into a PVC Tee piece such that the electrode tips
are submerged in the water flowing through the manifold in which the tee is
usually fitted. The probe should be positioned with the black markers on the
probe aligned with the black markers on the manifold Tee. This ensures that
the 2 electrodes of the probe are positioned symmetrically with respect to the
direction of water flow. See the photograph and diagrams below:
The probe’s electrodes should periodically be cleaned to maintain accurate TDS
measurements. The frequency of cleaning required will vary from one
application to another. In a new installation, it is recommended that the probe
be cleaned after 2 weeks of service.
To clean the probe, first unplug the probe lead and unscrew the probe from the
manifold. The probe can normally be cleaned using a cloth or paper towel.
Occasionally the probe’s carbon electrodes may be coated with substances
which requires more vigorous cleaning (this coating may not always be visible).
To clean a coated electrode, use a fine grit abrasive, such as emery paper.
After cleaning, apply more Teflon®tape to the probe thread and screw back
into the manifold. The controller should always be calibrated after probe
cleaning.
DIRECTION
OF FLOW

Page 9 of 95
3. Controller Functionality
3.1 Menu Logic
The DIGICHEM Plus+ has an advanced but very user-friendly menu system:
•The menu structure is circular
•The relevant menu item, or programmed value flashes on the display, and
is shown as bold letters or numbers when explained in this instruction
manual.
•Up & Down arrow pushbuttons allow you to scroll through the menu items
and to increase/decrease programmed settings
•The MAIN MENU expands to several levels of SUB MENUS when pressing
ENTER on various menu items
•The BACK pushbutton can be pressed at any time to exit from a current
menu to a previous menu screen, or to not save any edited settings
•The LCD is backlit
The MAIN MENU of the controller is illustrated as follows:
(Software ver 0.80 & later)
Main Menu
1245 TDS [ 750]BLEED
490 mV [ 500] DOSE
7.67pH [ 7.50] DOSE
INHB DISP
<MAIN MENU>
►SETUP MENU
TEST OUTPUTS
MANUAL DOSE
<MAIN MENU>
►CALIBRATION
ALARM PARAMETERS
ALARM OVERRIDE
X 3
X 3
X 3
X 3
Press
to access
menu item
Press
to exit
Hold
<MAIN MENU>
►TIME & DATE
FACTORY SETTINGS
SETUP MENU
X 2
X 2
Note: If password protection is enabled, the controller will ask you to enter
your password before allowing you to enter this menu.

Page 10 of 95
3.2 Pushbuttons
The DIGICHEM Plus+ has 4 pushbuttons each of which have dual functions:
1. Scroll UP (Time & Date)
2. Scroll DOWN (Main Menu)
3. ENTER (Reset)
4. BACK (View Settings)
•The Scroll UP and DOWN pushbuttons allows you to scroll in both
directions in the circular menus. Once a menu item has been selected and
there is a value to program, the Scroll pushbuttons allow you to increase or
decrease the number programmed.
•The ENTER pushbutton allows you to enter a part of the program that
you have selected. It also accepts any numbers programmed with the
Scroll pushbuttons.
•The BACK pushbutton allows you to exit from any menu, as well as to
exit from any screen without saving values, should you have changed any
values without pushing the ENTER pushbutton.
•If the Scroll UP (Time & Date) pushbutton is pressed momentarily in
NORMAL MODE (explained in section 4.1), the time and date is displayed.
To revert back to NORMAL MODE, press the pushbutton momentarily again.
The time and date is displayed as follows:
alternates with
1245 TDS [ 750]BLEED
490 mV [ 500] DOSE
7.67pH [ 7.50] DOSE
7 Jul 2008
1245 TDS [ 750]BLEED
490 mV [ 500] DOSE
7.67pH [ 7.50] DOSE
Mon 14:47-53 Week1
NOTE:
The Time & Date is programmable, but the Week No is automatically set.
Hence, if you have multiple controllers in the field, the Week No will be
the same on all (assuming the Time & Date are programmed correctly).
•To get into the menus of the DIGICHEM Plus+, hold down the Scroll DOWN
(Main Menu) pushbutton. The display will count down until you access the
menus. If password protection is enabled, the controller will ask you to
enter your password before allowing you to enter this menu.
•If you wish to cancel an alarm or any timers activated, press and hold the
ENTER (Reset) pushbutton until the display says:
Resetting…

Page 11 of 95
3.3 Controller Display Information
Notes: (v0.91 or later)
•If a pulse from a make-up water meter is received, a ‘+’ will be displayed
momentarily
•If a pulse from a bleed water meter is received, a ‘-’ will be displayed
momentarily
3.4 Comms Port
There is a Comms port on the front panel of the controller next to the LCD.
This is used to download data from the controller, and can also used to upload
new software versions should they be required.
The data is downloaded via the Comms port on the front panel of the
controller. An optional cable is required; P/N SP-XP2-COMCABLE-1, to perform
a direct download to a pc or laptop via the serial port.
However, some computers or laptops do not have a serial port, so a USB to
serial adapter will be required. These can be purchased from any electronics
store, or through CWC. Our part number: HOBO CABLE-USB-232.
The brand “Keyspan” is recommended.
4. Commissioning
CAUTION: Refer to previous section before reading this section

Page 12 of 95
4.1 Start-Up
Connect Power to the controller after installation. After a start-up sequence,
the controller automatically goes into NORMAL MODE. The display should read
the measured conductivity as well as the conductivity Setpoint within square
brackets (which alternates with the temperature as measured by the
conductivity probe).
Also displayed will be the measured pH, pH Setpoint within square brackets,
measured ORP value, and the ORP Setpoint within square brackets.
Depending on the measured values, the controller may also display control
functions of those illustrated in Section 3.3 for Controller Output Indication.
An example of a start up screen is shown below:
Other information that you may see on the display, which alternates with the
display above:
•When an alarm is reported, the actual alarm message will be periodically
displayed in the specific area on the main screen, for that alarm. Please
see the example below:
•When a flow switch is connected to the controller, each output is
suspended when there is no flow past the flow switch. The outputs that
would be suspended are only those that are selected via the Flow Switch
Menu.
1245 TDS [ 750]pause
200 mV [ 500]DOSE
9.17 pH [ 7.50]DOSE
NO FLOW
Example: No Flow Condition for Flow Switch Enabled on Bleed

Page 13 of 95
4.1.1 Start-Up Delay
Main Menu > SETUP MENU > GENERAL SETUP > START-UP DELAY
The Start-Up Delay feature is used to delay the operation of all control
functions of the DIGICHEM Plus+ Controller upon initial power up.
This could be used if it was necessary for the system water to circulate
adequately, for example to sufficiently mix chemicals in the water before
controlling the pH, ORP or conductivity.
This would also ensure the readings of these variables to first stabilise
before commencing control.
The example below illustrates setting the Start-Up Delay to 6 minutes (or
360 seconds).
Example: Increasing the Start-Up Delay from 0 seconds to 360 seconds
<GENERAL SETUP>
►START-UP DELAY
INHIBITOR SETUP
DISPERSANT SETUP
<START-UP DELAY>
COUNT-DOWN: 0000s
<START-UP DELAY>
COUNT-DOWN: 0300s
<START-UP DELAY>
COUNT-DOWN: 0300s
<START-UP DELAY>
COUNT-DOWN: 0360s
NOTE: The Start-Up delay will also take effect upon resumption of flow.

Page 14 of 95
4.2 Setting Time & Date
Main Menu > TIME & DATE
NOTE: The Week Number will be automatically set
4.3 Calibration
Main Menu > CALIBRATION
The Calibration menu has the following displays:
Calibration Menu
<CALIBRATION>
►CALIBRATE μS/TDS
CALIBRATE ORP
CALIBRATE pH
<CALIBRATION>
►CALIBRATE pH
CALIBRATE μS/TDS
CALIBRATE ORP
X 2
X 2
<MAIN MENU>
►CALIBRATION
ALARM PARAMETERS
TIME & DATE
Press
to access
menu item
Press
to return to
main menu
X 2
X 2

Page 15 of 95
4.3.1 Conductivity (TDS / µS) Calibration
Main Menu > CALIBRATION > CALIBRATE µs/TDS
IMPORTANT: Select the display in either µS or TDS before proceeding.
(Refer section 5.1.1)
Calibrating the TDS SLOPE
Main Menu > CALIBRATION > CALIBRATE µs/TDS > SLOPE CAL µS/TDS
Take a sample of water from the sample valve on the manifold and
measure the conductivity with a calibrated hand-held conductivity meter.
Alternatively, insert the Conductivity probe in a buffer solution of known
conductivity. Should the conductivity readout on the display differ from
the sample taken, calibrate the controller as follows:
Adjust the current reading via the Calibration Menu to the desired
reading.
Please see the example on the following page:

Page 16 of 95
Calibrating the µS/TDS ZERO
Main Menu > CALIBRATION > ZERO CAL µS/TDS
The zero is factory set so should not require calibration. However, if the
display reads above zero with the conductivity probe disconnected, or
with the probe dry, recalibrate the zero as follows:
1. Remove the probe from the manifold.
2. Dry the electrodes of the probe, so that there is zero (or minimal)
conductivity between the electrodes.
3. Wait until the reading on the LCD is stable. If the reading does not
settle to exactly 0, wait until it does not drop any further.
4. Go to the Calibrate Menu and set the Zero Calibration (see next page).
5. Screw the probe back into the manifold.
6. Perform the SLOPE calibration again.

Page 17 of 95
Alternative zero calibration procedure:
1. Disconnect the cable from the back of the probe.
2. Wait until the reading on the LCD is stable. If the reading does not
settle to exactly 0, wait until it does not drop any further.
3. Go to the Calibrate Menu and set the Zero Calibration (see below).
4. Re-connect the cable to the probe securely.
5. Perform the SLOPE calibration again.
Calibrating the Zero for µS/TDS
<CALIBRATION>
►CALIBRATE μS/TDS
CALIBRATE ORP
CALIBRATE pH
<CALIBRATE μS/TDS>
►SLOPE CAL. μS/TDS
ZERO CAL. μS/TDS
RESET μS/TDS CAL.
<ZERO CAL. μS/TDS>
Confirm? [NO ]
Calibrating...
<CALIBRATE μS/TDS>
►ZERO CAL. μS/TDS
RESET μS/TDS CAL.
SLOPE CAL. μS/TDS
<ZERO CAL. μS/TDS>
Confirm? [YES]
Ensure cable is
disconnected from
probe, or the probe is
completely dry before
confirming
0TDS [ 750]BLEED
495 mV [ 500] DOSE
7.52 pH [ 7.50] DOSE
To main screen
Resetting the TDS CALIBRATION
Main Menu > CALIBRATION > RESET µS/TDS CAL.
If you inadvertently calibrate the zero and/or slope to the incorrect
values, and you cannot recover by repeating the normal calibration
procedure, then you can reset the calibration and start again.
See diagram on the following page to reset the calibration:

Page 18 of 95
Resetting the µS/TDS Calibration
<CALIBRATION>
►CALIBRATE μS/TDS
CALIBRATE ORP
CALIBRATE pH
<RESET μS/TDS CAL.>
Reset? [NO ]
<ZERO CAL. μS/TDS>
Reset? [YES]
X 2
<CALIBRATE μS/TDS>
►RESET μS/TDS CAL.
SLOPE CAL. μS/TDS
ZERO CAL. μS/TDS
<CALIBRATE μS/TDS>
►SLOPE CAL. μS/TDS
ZERO CAL. μS/TDS
RESET μS/TDS CAL.
0TDS [ 750]BLEED
495 mV [ 500] DOSE
7.52 pH [ 7.50] DOSE
To main screen
Please Wait...
4.3 2 ORP mV Calibration
Main Menu > CALIBRATION > CALIBRATE ORP
NOTE: The DIGICHEM Plus+ is factory calibrated, so under normal
circumstances, calibration is not required. However, if you need
to calibrate, or verify the reading in buffer solutions, proceed as
follows:
Putting the controller into CALIBRATE mode automatically bypasses the
solution ground probe. This enables you to use a mV simulator connected
to the controller, or enables you to insert the ORP sensor in a buffer
solution without the solution ground probe. This ensures you get an
accurate reading on the controller.
The ground probe is automatically enabled again when you exit ORP
calibration.

Page 19 of 95
Calibrating the ORP SLOPE
Main Menu > CALIBRATION > CALIBRATE ORP > SLOPE CAL. ORP
Before you proceed, set the mV simulator to the desired setting, or put the
ORP sensor in the buffer solution.
IMPORTANT: Wait for the measured mV reading to stabilise before
proceeding.
Example: Calibrating the ORP Slope Value from 517mV to 475mV
<CALIBRATION>
►CALIBRATE ORP
CALIBRATE pH
CALIBRATE μS/TDS
<CALIBRATE ORP>
►SLOPE CAL. ORP
ZERO CAL. ORP
RESET ORP CAL.
<SLOPE CAL. ORP>
517 mV
ENTER to Calibrate
BACK to Exit
<SLOPE CAL. ORP>
ORP(mV) 0517
<SLOPE CAL. ORP>
ORP(mV) 0417
<SLOPE CAL. ORP>
ORP(mV) 0417
Calibrating...
<SLOPE CAL. ORP>
ORP(mV) 0475
To Calibration screen –
display should now read
475 mV
Ensure ORP probe is in
standard solution before
proceeding. Do not
immerse ground probe in
solution.
Press
when reading
stabilises or
Press
to return to the
main screen once
reading has been
calibrated

Page 20 of 95
Calibrating the ORP ZERO
Main Menu > CALIBRATION > CALIBRATE ORP > ZERO CAL. ORP
The zero is factory set so should not require calibration. However, if you
want to set the zero, you will require a mV simulator with a 0mV or pH7
setting. Alternatively, you can short circuit the BNC input for this
procedure.
Before you proceed, set the mV simulator to the zero setting (pH7 setting
= 0mV)
IMPORTANT: Wait for the measured mV reading to stabilise before
proceeding. This reading should be very close to zero.