TSI Instruments 8682-KF1 Configuration guide

Manual Supplement
Project:
Date:
Page 1 of 23 Released 2/15/02
Model Number: 8682-KF1
Product/System Title: Adaptive Offset Controller with 2-Point
Flow Calibration and Reheat Control
Contents of this manual supplement include:
1) How to use this Manual Supplement
2) Sequence of operation
3) Menu item descriptions
• menu structure drawing
• description of software additions
• listing of software deletions
4) Modbus Communications
5) Wiring Diagrams
How to Use This Manual Supplement
This supplement replaces pages 13-36, Menu and Menu Items and pages 50-51, Appendix B Wiring
Information of the Model 8682 SUREFLOW Adaptive Offset Controller, Operation Service Manual
(P/N 1980288).
This supplement describes the menus and menu items used to configure and program the controller
and how to wire each component.
Sequence of Operation
The Model 8682-KF1 uses the standard Model 8682 pressure and tracking control algorithm. The
Model 8682-KF1 also features temperature control. The temperature control scheme provides
modulation of supply volume for cooling and modulation of a reheat valve for heating.
The Model 8682-KF1 laboratory control system uses a through-the-wall room pressure sensor to
measure pressure differential (direct pressure measurement) between the laboratory and corridor
(reference space), and receives temperature information from the thermostat (0-10 VDC, 50-85°F).
The pressure sensor is located on the corridor (reference space) side of the wall. The Model
8682-KF1 laboratory controller continuously monitors the thermostat information. The Model
8682-KF1 control algorithm modulates supply and general exhaust air flows to provide adequate
fume hood replacement air while maintaining room pressure differential and temperature control.

Manual Supplement
Project:
Date:
Page 2 of 23 Released 2/15/02
Pressure Control Sequence:
The Model 8682-KF1 receives the pressure differential signal from the pressure sensor. If
pressure is at set point, the control algorithm maintains the offset. If pressure is not at set
point, the offset value is changed until pressure is maintained, or the minimum or maximum
offset value is reached. If the offset value:
Increases, the supply air is reduced until one of 3 events occur:
• Pressure set point is reached. The Model 8682-KF1 maintains the new offset.
• The offset range is exceeded. The offset will be at maximum attempting to reach
pressure set point. An alarm will trigger to inform the user pressure differential
is not being maintained.
• Supply air minimum is reached. The general exhaust begins to open (was
closed) to maintain pressure differential.
Decreases, the supply air increases until one of 3 events occur:
• Pressure set point is reached. The Model 8682-KF1 maintains the new offset.
• The offset range is exceeded. The offset will be at minimum attempting to reach
pressure set point. An alarm will trigger to inform the user pressure differential
is not being maintained.
• Supply air maximum is reached. The alarm will trigger to inform the user
pressure differential is not being maintained.
NOTE: The pressure differential is a slow secondary control loop. The system initially starts
with a calculated offset value and then slowly adjusts the offset value to maintain
pressure differential.
The Model 8682-KF1 continuously monitors and displays pressure differential between the
laboratory and corridor (reference space). When the pressure differential is adequate, a green
light indicates a safe pressure differential is being maintained. Room pressure alarm set
points, configured into the controller, activate a red light and audible alarm when the room
pressure becomes insufficient or too great. In addition to a local indication of room pressure,
alarm contacts and RS 485 communications may be used to provide extensive information to a
building management system.
Temperature Control Sequence:
The 8682-KF1 receives a temperature input from a 0-10 volt (50-85°F) thermostat. The Model
8682-KF1 controller maintains temperature control by:
(1) Controlling supply and general exhaust for ventilation and cooling
(2) Controlling the reheat coil for heating

Manual Supplement
Project:
Date:
Page 3 of 23 Released 2/15/02
The Model 8682-KF1 has three supply flow minimum set points. The ventilation set point is
the minimum flow volume required to meet ventilation needs of the laboratory (ACPH). The
temperature supply set point (TEMP MIN) is the minimum flow required to meet temperature
needs of the laboratory. The unoccupied set point is the minimum flow required when the lab
is not occupied. All of these set points are configurable.
The Model 8682-KF1 continuously compares the temperature set point to the actual space
temperature. If set point is being maintained, no changes are made. If set point is not being
maintained, and the space temperature is rising the controller will first modulate the reheat
valve closed. If the reheat valve is closed the controller will then increase the supply volume
to meet the cooling demand. If the space temperature is falling the controller will first reduce
the supply volume. If the supply volume reaches its minimum, ventilation or hood demand,
the controller will then modulate the reheat coil open to meet the heating demand.
If the general exhaust is in the closed position and fume hood loads require additional
replacement air, the Model 8682-KF1 will override ventilation or temperature set points to
modulate supply for pressurization control. Temperature will then be controlled by reheat in
this sequence.

Manual Supplement
Project:
Date:
Page 4 of 23 Released 2/15/02
Menu and Menu Items
The SUREFLOW is a very versatile device that can be configured to meet your specific application.
This section describes all of the menu items available to program and change. Changing any item is
accomplished by using the keypad, or if communications are installed, through the RS-485
Communications port. If you are unfamiliar with the keystroke procedure please see Programming
Software for a detailed explanation. This section provides the following information:
- Complete list of menu and all menu items.
- Gives the menu or programming name.
- Defines each menu item’s function; what it does, how it does it, etc..
- Gives the range of values that can be programmed.
- Gives default item value (how it shipped from factory).
The menus covered in this section are divided into groups of related items to ease programming. As
an example all set points are in one menu, alarm information in another, etc. The manual follows
the menus as programmed in the controller. The menu items are always grouped by menu and then
listed in menu item order, not alphabetical order. Figure 1, on the next 2 pages, shows a chart of all
the Model 8682-KF1 controller menu items.
SETPOINTS
SET POINT
REM SETPOINT
VENT MIN SET
TEMP MIN SET
UNOCCUPY SET
MAX SUP SET
MIN EXH SET
MIN OFFSET
MAX OFFSET
TEMP SETP
ACCESS CODE
ALARM
LOW ALARM
HIGH ALARM
REM LOW ALM
REM HIGH ALM
MIN SUP ALM
MAX EXH ALM
ALARM RESET
AUDIBLE ALM
ALARM DELAY
MUTE TIMEOUT
ACCESS CODE
CONFIGURE
DISPLAY AVG
UNITS
ROOM VOLUME
EXH CONFIG
ACCESS CODE
CALIBRATION
SENSOR ZERO
SENSOR SPAN
ELEVATION
TEMP CAL
ACCESS CODE
CONTROL
SPEED
SENSITIVITY
CONTROL SIG
TEMP CONTROL
KC VALUE
TI VALUE
KC OFFSET
TEMP KC VAL
ACCESS CODE
SYSTEM FLOW
TOT SUP FLOW
TOT EXH FLOW
OFFSET VALUE
SUP SET POINT
EXH SET POINT
ACPH
ACCESS CODE
FLOW CHECK
HD1 FLOW IN
HD2 FLOW IN
HD3 FLOW IN
HD4 FLOW IN
HD5 FLOW IN
HD6 FLOW IN
HD7 FLOW IN
EX1 FLOW IN
EX2 FLOW IN
SP1 FLOW IN
SP2 FLOW IN
SP3 FLOW IN
SP4 FLOW IN
ACCESS CODE
DIAGNOSTICS
CONTROL SUP
CONTROL EXH
CONTROL TEMP
SENSOR INPUT
SENSOR STAT
TEMP INPUT
OCCUPANT SWT
KEY SWITCH
LOW ALM REL
HIGH ALM REL
LOW SUP REL
HIGH EXH REL
PRESS AOUT
SUPPLY AOUT
EXHAUST AOUT
ACCESS CODE

Manual Supplement
Project:
Date:
Page 5 of 23 Released 2/15/02
INTERFACE
NET PROTOCOL
NET ADDRESS
OUTPUT RANGE
OUTPUT SIG
MAX FLOW OUT
ACCESS CODE
SUPPLY FLOW
SP1 DCT AREA
SP2 DCT AREA
SP3 DCT AREA
SP4 DCT AREA
SP1 FLO ZERO
SP2 FLO ZERO
SP3 FLO ZERO
SP4 FLO ZERO
FLO STA TYPE
XDCR OUT
TOP VELOCITY
SP LOW SETP
SP HIGH SETP
SP1 LOW CAL
SP1 HIGH CAL
SP2 LOW CAL
SP2 HIGH CAL
SP3 LOW CAL
SP3 HIGH CAL
SP4 LOW CAL
SP4 HIGH CAL
RESET CAL
ACCESS CODE
HOOD FLOW
HD1 DCT AREA
HD2 DUCT AREA
HD3 DUCT AREA
HD4 DUCT AREA
HD5 DUCT AREA
HD6 DUCT AREA
HD7 DUCT AREA
HD1 FLO ZERO
HD2 FLO ZERO
HD3 FLO ZERO
HD4 FLO ZERO
HD5 FLO ZERO
HD6 FLO ZERO
HD7 FLO ZERO
FLO STA TYPE
XDCR OUT
TOP VELOCITY
HD1 LOW CAL
HD1 HIGH CAL
HD2 LOW CAL
HD2 HIGH CAL
HD3 LOW CAL
HD3 HIGH CAL
HD4 LOW CAL
HD4 HIGH CAL
HD5 LOW CAL
HD5 HIGH CAL
HD6 LOW CAL
HD6 HIGH CAL
HD7 LOW CAL
HD7 HIGH CAL
MIN HD1 FLOW
MIN HD2 FLOW
MIN HD3 FLOW
MIN HD4 FLOW
MIN HD5 FLOW
MIN HD6 FLOW
MIN HD7 FLOW
RESET CAL
ACCESS CODE
EXHAUST FLOW
EX1 DCT AREA
EX2 DCT AREA
EX1 FLO ZERO
EX2 FLO ZERO
FLO STA TYPE
XDCR OUT
TOP VELOCITY
EX LOW SETP
EX HIGH SETP
EX1 LOW CAL
EX1 HIGH CAL
EX2 LOW CAL
EX2 HIGH CAL
RESET CAL
ACCESS CODE
Figure 1: Menu Items - Model 8682-KF1 Controller

Manual Supplement
Project:
Date:
Page 6 of 23 Released 2/15/02
Software Additions
The Model 8682-KF1 has additional programmable software items. The unit works similar to a
standard model, with several additions.
SET POINT MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT VALUE)
REM SETPOINT The REM SET POINT item sets the pressure set point
upon activation of a changeover switch.
Pressure Differential is not maintained by direct pressure
control; i.e. modulating dampers in response to pressure
changes. The pressure signal is an AOC input, that is
used to calculate the required air flow offset value. The
calculated offset value changes the supply (or exhaust)
flow volume which changes the pressure differential.
When the calculated offset value is less than the MIN
OFFSET or greater than the MAX OFFSET, pressure
control will not be maintained.
-0.19500 “H2O to
+0.19500 “ H2O
(-0.0020 “ H2O)
TEMP SETP The TEMP SETP item sets the temperature set point of
the space.
50 °F - 85 °F
(68 °F)

Manual Supplement
Project:
Date:
Page 7 of 23 Released 2/15/02
ALARM MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT VALUE)
REM LOW ALM The REM LOW ALM menu item sets the remote low
pressure alarm set point. A low alarm condition is
defined as when the room pressure falls below or goes in
the opposite direction of the REM LOW ALM set point.
The REM LOW ALM is only activated when the
controller is at the REM SET POINT.
OFF
-0.18500 “ H2O to
+0.18500 “ H2O
(OFF)
REM HIGH ALM The REM HIGH ALM menu item sets the remote high
pressure alarm set point. A high alarm condition is
defined as when the room pressure exceeds (is more
positive or more negative than) the REM HIGH ALM set
point. The REM HIGH ALM is only activated when the
controller is at the REM SET POINT.
OFF
-0.18500 “ H2O to
+0.18500 “ H2O
(OFF)
MAX EXH ALM The MAX EXH ALM sets the maximum exhaust flow
alarm set point. A maximum exhaust alarm is defined as
when the total exhaust exceeds the MAX EXH ALM set
point.
Note: The Model 8682-KF1 has a relay contact that
corresponds to the MAX EXH ALM. This alarm
relay replaces the LOW EXHAUST FLOW
ALARM relay (Digital Alarm Output 2), (AOC,
pins 56 and 57).
OFF
0 - 30,000 CFM
(OFF)
CALIBRATION MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
TEMP CAL The TEMP CAL is used to enter the actual space
temperature. This adjustment offsets the temperature
sensor curve.
50 °F - 85 °F

Manual Supplement
Project:
Date:
Page 8 of 23 Released 2/15/02
CONTROL MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT VALUE)
TEMP
CONTROL
The TEMP CONTROL item determines the control
signal’s output direction. As an example: If the control
system closes the reheat valve instead of opening this
valve, this option will reverse the control signal to now
open the valve.
DIRECT OR REVERSE
(DIRECT)
TEMP KC VAL The TEMP KC VAL item provides the user with the
ability to manually change the control loop speed.
The TEMP KC VALUE item is used to read and change
the gain control coefficient. When this item is entered, a
value for Kc is indicated on the display. If the SUREFLOW
is not controlling correctly, the Kc gain control
coefficient may need adjusting. Decreasing Kc will slow
the control system down, which will increase stability.
Increasing Kc will increase the control system speed,
which may cause system instability.
0 to 1000
(100)

Manual Supplement
Project:
Date:
Page 9 of 23 Released 2/15/02
FLOW CHECK MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT VALUE)
SP3 FLOW IN
SP4 FLOW IN
The SP# FLOW IN menu item displays the current supply
air flow. This item is a diagnostics tool used to compare
the supply flow to a traverse of the duct work. If flow error
is greater than 10%, adjust the SP# DUCT AREA until the
error is within 10%. In addition, summing the SP# FLOW
IN should equal the TOT SUP FLOW.
When a volt meter is hooked to the flow station output, a
voltage should be displayed. The exact voltage displayed is
relatively unimportant. It is more important that the voltage
is changing, which indicates the flow station is working
correctly. For a 0.5 “H2O transducer,
0 volts displayed equals zero flow
5 volts displayed equals 2832 ft/min x duct area
(ft2) - pressure based flow station
5 volts displayed equals TOP VELOCITY x duct
area (ft2) - linear based flow station
NONE: Read only value
(NONE)

Manual Supplement
Project:
Date:
Page 10 of 23 Released 2/15/02
DIAGNOSTICS MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
CONTROL
TEMP
The CONTROL TEMP item manually changes the control
output signal to the reheat valve. When this item is entered, a
number between 0 and 255 will be shown on the display
indicating the control output value. Pressing the ▲/▼keys
changes the count on the display. Pressing the ▲key increases
the displayed value, while pressing the ▼key decreases the
displayed value. The reheat control valve should modulate as the
number changes. Depending on the valve, 0 or 255 is full open.
A count of 150 should position the valve approximately 1/2 open.
WARNING: The CONTROL TEMP function overrides the
AOC control signal. Adequate space temperature will NOT be
maintained while in this item.
0 - 255
TEMP INPUT The TEMP INPUT item shows the current temperature reading.
OCCUPANT
SWT
The OCCUPANT SWT item shows the status of the occupancy
switch input. This can be used to test the occupancy switch
connection.
NORMAL
UNOCCUPIED
KEY SWITCH The KEY SWITCH item shows the status of the key switch,
which selects either the main or the remote set points. If the
KEY SWITCH item displays OPEN, then the main set points are
in use. If the KEY SWITCH item displays CLOSED, then the
remote set points are used.
OPEN
CLOSED
HIGH EXH REL The HIGH EXH REL item is used to change the state of the high
exhaust relay. When the HIGH EXH REL is entered, the display
will indicate either OPEN or CLOSED. The ▲/▼keys are used
to toggle the state of the relay. The ▲key will OPEN the alarm
contact. Pressing the ▼key will CLOSE the alarm contact.
When the contact is closed, the relay is in an alarm condition.
OPEN
CLOSED

Manual Supplement
Project:
Date:
Page 11 of 23 Released 2/15/02
SUPPLY FLOW MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT)
SP3 DUCT AREA
SP4 DUCT AREA
The SP# DUCT AREA item inputs the supply duct size. The
duct size is needed to compute the flow out of the supply duct.
This item requires a flow station to be mounted in each supply
duct.
If the DIM displays English units, area must be entered in square
feet. If metric units are displayed, area must be entered in square
meters.
0 - 10 ft2
0 - 0.95 m2
(0)
The DIM does not
compute duct area.
The area must first
be calculated and
then entered into
the unit.
SP3 FLO ZERO
SP4 FLO ZERO
The SP# FLO ZERO item establishes the flow station zero flow
point. A zero or no flow point needs to be established in order to
obtain a correct flow measurement output (see Calibration
section).
All pressure based flow stations need to have a SP# FLO ZERO
established on initial set up. Linear flow stations with a
1-5 VDC output also need to have a SP# FLO ZERO
established. Linear flow stations with a 0-5 VDC output do not
need a SP# FLO ZERO.
NONE
XDCR OUT The XDCR OUT menu item allows the user to select the
maximum range of the pressure transducer used with the flow
stations.
0.1, 0.2, 0.3, 0.4,
0.5 “H2O
25, 50, 75, 100, 125
pascals
(0.5 in H2O
125 pascals)
SP LOW SETP The SP LOW SETP menu item sets the supply damper position
for supply low flow calibration.
0-255
SP HIGH SETP The SP HIGH SETP menu item sets the supply damper position
for the supply high flow calibration.
0-255

Manual Supplement
Project:
Date:
Page 12 of 23 Released 2/15/02
SUPPLY FLOW MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT)
SP1 LOW CAL
SP2 LOW CAL
SP3 LOW CAL
SP4 LOW CAL
The SP# LOW CAL menu items display the currently measured
supply flow rate and the calibrated value for that supply flow.
The supply dampers will move to the SP LOW SETP damper
position for the low calibration. The calibrated supply flow can
be adjusted using the ▲/▼keys to make it match a reference
measurement. Pressing the SELECT key will save the new
calibration data.
SP1 HIGH CAL
SP2 HIGH CAL
SP3 HIGH CAL
SP4 HIGH CAL
The SP# HIGH CAL menu items display the currently
measured supply flow rate and the calibrated value for that
supply flow. The supply dampers will move to the SP HIGH
SETP damper position for the low calibration. The calibrated
supply flow can be adjusted using the ▲/▼keys to make it
match a reference measurement. Pressing the SELECT key will
save the new calibration data.
RESET CAL The RESET CAL menu item zeroes out the calibration
adjustments for the 4 supply flows. When this menu item is
entered, the 8682-KF1 will prompt the user to verify that they
want to do this. Press the SELECT key to reset the calibrations,
and the MENU key to reject it.

Manual Supplement
Project:
Date:
Page 13 of 23 Released 2/15/02
HOOD FLOW MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT)
XDCR OUT The XDCR OUT menu item allows the user to select the
maximum range of the pressure transducer used with the flow
stations.
0.1, 0.2, 0.3, 0.4,
0.5 “H2O
25, 50, 75, 100, 125
pascals
(0.5 in H2O
125 pascals)
HD1 LOW CAL
HD2 LOW CAL
HD3 LOW CAL
HD4 LOW CAL
HD5 LOW CAL
HD6 LOW CAL
HD7 LOW CAL
The HD# LOW CAL menu items display the currently measured
fume hood flow rate and the calibrated value for that fume hood
flow. The calibrated hood flow can be adjusted using the ▲/▼
keys to make it match a reference measurement. Pressing the
SELECT key will save the new calibration data.
HD1 HIGH CAL
HD2 HIGH CAL
HD3 HIGH CAL
HD4 HIGH CAL
HD5 HIGH CAL
HD6 HIGH CAL
HD7 HIGH CAL
The HD# HIGH CAL menu items display the currently measured
fume hood flow rate and the calibrated value for that fume hood
flow. The calibrated hood flow can be adjusted using the ▲/▼
keys to make it match a reference measurement. Pressing the
SELECT key will save the new calibration data.
MIN HD1 FLOW
MIN HD2 FLOW
MIN HD3 FLOW
MIN HD4 FLOW
MIN HD5 FLOW
MIN HD6 FLOW
MIN HD7 FLOW
The MIN HD# FLOW menu items adjust the minimum flow
value for each fume hood input. Use this menu item if the fume
hood flow measurements are too low when the sash is closed.
RESET CAL The RESET CAL menu item zeroes out the calibration
adjustments for the 7 hood flows. When this menu item is
entered, the 8682-KF1 will prompt the user to verify that they
want to do this. Press the SELECT key to reset the calibrations,
and the MENU key to reject it.

Manual Supplement
Project:
Date:
Page 14 of 23 Released 2/15/02
EXHAUST FLOW MENU
SOFTWARE
NAME ITEM DESCRIPTION
ITEM RANGE
(DEFAULT)
XDCR OUT The XDCR OUT menu item allows the user to select the
maximum range of the pressure transducer used with the flow
stations.
0.1, 0.2, 0.3, 0.4,
0.5 “H2O
25, 50, 75, 100, 125
pascals
(0.5 in H2O
125 pascals)
EX LOW SETP The EX LOW SETP menu item sets the general exhaust damper
position for general exhaust low flow calibration.
0-255
EX HIGH SETP The EX HIGH SETP menu item sets the general exhaust damper
position for the general exhaust high flow calibration.
0-255
EX1 LOW CAL
EX2 LOW CAL
The EX LOW CAL menu items display the currently measured
general exhaust flow rate and the calibrated value for that general
exhaust flow. The calibrated general exhaust can be adjusted
using the ▲/▼keys to make it match a reference measurement.
Pressing the SELECT key will save the new calibration data.
EX1 HIGH CAL
EX2 HIGH CAL
The EX HIGH CAL menu items display the currently measured
general exhaust flow rate and the calibrated value for that general
exhaust flow. The calibrated general exhaust flow can be
adjusted using the ▲/▼keys to make it match a reference
measurement. Pressing the SELECT key will save the new
calibration data.
RESET CAL The RESET CAL menu item zeroes out the calibration
adjustments for the 7 hood flows. When this menu item is
entered, the 8682-KF1 will prompt the user to verify that they
want to do this. Press the SELECT key to reset the calibrations,
and the MENU key to reject it.
Software Deletions
The following menu items have been deleted from the unit:
SETPOINTS menu: TEMP LOW
TEMP HIGH
ALARM menu: MIN EXH ALM
DIAGNOSTICS menu LOW EXH REL

Manual Supplement
Project:
Date:
Page 15 of 23 Released 2/15/02
MODBUS Communications
Modbus communications are installed in the Model 8682-KF1 adaptive offset room pressure
controllers. This document provides the technical information needed to communicate between the
host DDC system and the Model 8682-KF1 units. This document assumes the programmer is
familiar with Modbus protocol. Further technical assistance is available from TSI if your question
is related to TSI interfacing to a DDC system. If you need further information regarding Modbus
programming in general, please contact:
Modicon Incorporated
One High Street
North Andover, MA 01845
Phone [phone]
The Modbus protocol utilizes the RTU format for data transfer and Error Checking. Check the
Modicon Modbus Protocol Reference Guide (PI-Mbus-300) for more information on CRC
generation and message structures.
The messages are sent at 9600 baud with 1 start bit, 8 data bits, and 2 stop bits. Do not use the
parity bit. The system is set up as a master slave network. The TSI units act as slaves and respond
to messages when their correct address is polled.
Blocks of data can be written or read from each device. Using a block format will speed up the
time for the data transfer. The size of the blocks is limited to 20 bytes. This means the maximum
message length that can be transferred is 20 bytes. The typical response time of the device is
around 0.05 seconds with a maximum of 0.1 seconds.
Unique to TSI
The list of variable addresses shown below skips some numbers in the sequence due to internal
Model 8682-KF1 functions. This information is not useful to the DDC system and is therefore
deleted. Skipping numbers in the sequence will not cause any communication problems.
All variables are outputted in English units: ft/min, CFM, or inches H20. The room pressure
control setpoints and alarms are stored in ft/min. The DDC system must convert the value to inches
of water if that is desired. The equation is given below.
Pressure in Inches H2O = 6.2*10-8*(Velocity in ft/min / .836)2
XRAM Variables
These variables can be read using Modbus command 03 Read Holding Registers. They can be
written to using Modbus command 16 Preset Multiple Regs. Many of these variables are the same
“menu items” that are configured from the SUREFLOW keypad. The calibration and control items
are not accessible from the DDC system. This is for safety reasons, since each room is individually
setup for maximum performance.

Manual Supplement
Project:
Date:
Page 16 of 23 Released 2/15/02
8682-KF1 Variable List
Variable Name Variable
Address
Input Provided to Master
System
Integer DDC system
receives
Software Version 0 Current Software Version 1.00 = 100
Controller Type 1 Controller Model Number 8682
Emergency Mode 2 Emergency Mode Control
Write only variable.
0 Leave emergency mode
1 Enter emergency mode
Control Mode 3 Control mode of device. 0 Normal
1 Unoccupied (Setback)
Status Index 4 Status of SUREFLOW device 0 Normal
1 Dim Data Error
2 Alarm = Low Pressure
3 Alarm = High Pressure
4 Alarm = Min Supply
5 Alarm = Max Exhaust
6 Data Error
7 Cal Error
8 Emergency Mode
Room Velocity 5 Velocity of room pressure Displayed in ft/min.
Room Pressure 6 Room Pressure Displayed in inches H2O.
Host DDC system must
divide by 100,000 to
report pressure correctly
Total Supply Flow 7 Total supply into laboratory Displayed in CFM.
Total Exhaust
Flow
8 Total exhaust out of laboratory Displayed in CFM.
Offset Setpoint 9 Current offset setpoint Displayed in CFM.
Air changes per
hour
10 Calculated room air changes Displayed in number per
hour. Host DDC system
must divide value by 10 to
report ACPH correctly.
Fume Hood 1
Flow
11 Flow measured by flow station
connected to hood input #1.
Displayed in CFM.
Fume Hood 2
Flow
12 Flow measured by flow station
connected to hood input #2.
Displayed in CFM.
Fume Hood 3
Flow
13 Flow measured by flow station
connected to hood input #3.
Displayed in CFM.
Fume Hood 4
Flow
14 Flow measured by flow station
connected to hood input #4.
Displayed in CFM.

Manual Supplement
Project:
Date:
Page 17 of 23 Released 2/15/02
Variable Name Variable
Address
Input Provided to Master
System
Integer DDC system
receives
Fume Hood 5
Flow
15 Flow measured by flow station
connected to hood input #5.
Displayed in CFM.
Fume Hood 6
Flow
16 Flow measured by flow station
connected to hood input #6.
Displayed in CFM.
Fume Hood 7
Flow
17 Flow measured by flow station
connected to hood input #7.
Displayed in CFM.
Exhaust 1 Flow 18 Flow measured by flow station
connected to general exhaust
input #1.
Displayed in CFM.
Exhaust 2 Flow 19 Flow measured by flow station
connected to general exhaust
input #2.
Displayed in CFM.
Supply 1 Flow 20 Flow measured by flow station
connected to supply flow input #1
Displayed in CFM.
Supply 2 Flow 21 Flow measured by flow station
connected to supply flow input #2
Displayed in CFM.
Supply 3 Flow 22 Flow measured by flow station
connected to supply flow input #3
Displayed in CFM.
Supply 4 Flow 23 Flow measured by flow station
connected to supply flow input #4
Displayed in CFM.
Pressure Setpoint 24 Pressure control setpoint Displayed in ft/min.
Min Vent
Setpoint
25 Minimum flow setpoint for
ventilation.
Displayed in CFM.
Min Temp
Setpoint
26 Minimum flow setpoint for
temperature control.
Displayed in CFM.
Unoccupied Min
Setpoint
27 Unoccupied (Setback) minimum
flow setpoint.
Displayed in CFM.
Low Alarm 28 Low pressure alarm setpoint Displayed in ft/min.
High Alarm 29 High pressure alarm setpoint Displayed in ft/min.
Min Supply
Alarm
30 Minimum supply flow alarm Displayed in CFM.
Max Exhaust
Alarm
31 Maximum general exhaust alarm Displayed in CFM.
Min Offset
Setpoint
32 Minimum offset setpoint Displayed in CFM.
Max Offset
Setpoint
33 Maximum offset setpoint Displayed in CFM.
Max Supply
Setpoint
34 Maximum supply setpoint Displayed in CFM.

Manual Supplement
Project:
Date:
Page 18 of 23 Released 2/15/02
Variable Name Variable
Address
Input Provided to Master
System
Integer DDC system
receives
Min Exhaust
Setpoint
35 Minimum exhaust setpoint Displayed in CFM.
Temp Setpoint 36 Temperature setpoint Displayed in °F
Output Range 38 Room pressure analog output
range
0 Low
1 High
Output Mode 39 Analog output signal 0 4-20 ma
1 0-10 volt
Elevation 40 Elevation above sea level 0-10,000 feet. Displayed in
1,000 feet increments.
Hood 1 Duct Area 41 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Hood 2 Duct Area 42 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Hood 3 Duct Area 43 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Hood 4 Duct Area 44 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Hood 5 Duct Area 45 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Hood 6 Duct Area 46 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Hood 7 Duct Area 47 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Exhaust 1 Duct
Area
48 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Exhaust 2 Duct
Area
49 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Supply 1 Duct
Area
50 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.

Manual Supplement
Project:
Date:
Page 19 of 23 Released 2/15/02
Variable Name Variable
Address
Input Provided to Master
System
Integer DDC system
receives
Supply 2 Duct
Area
51 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Room Volume 52 Room volume in cubic feet
(needed or ACPH calculation)
Displayed in cubic feet.
Supply 3 Duct
Area
53 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Control Action 56 Control output signal direction 0 Reverse
1 Direct
Supply 4 Duct
Area
60 Duct area in square feet Host DDC system must
divide value by 1,000 to
report duct area correctly.
Network Protocol 61 Network protocol for RS485
communications
0 Modbus
1 Cimetrics
Network Address 62 Communication address of device Range is 1-247
Flow Output
Range
87 Flow analog output range setting 0 1,000 CFM
1 5,000 CFM
2 10,000 CFM
3 20,000 CFM
5 50,000 CFM
Hood Flow
Station Type
96 Type of flow station being used
in fume hoods.
0 Pressure based
1 Linear
Exhaust Flow
Station Type
97 Type of flow station being used
in general exhaust.
0 Pressure based
1 Linear
Supply Flow
Station Type
98 Type of flow station being used
in supply.
0 Pressure based
1 Linear
Hood Top
Velocity
99 Fume hood maximum velocity
range of flow station.
0-5,000 ft/min
Exhaust Top
Velocity
100 General exhaust maximum
velocity range of flow station.
0-5,000 ft/min
Supply Top
Velocity
101 Supply maximum velocity range
of flow station.
0-5,000 ft/min
Exhaust
Configuration
102 Configuration of exhaust duct
work.
0 Unganged
1 Ganged
Alarm Mode 103 Latched or unlatched alarms 0 Unlatched
1 Latched

Manual Supplement
Project:
Date:
Page 20 of 23 Released 2/15/02
Variable Name Variable
Address
Input Provided to Master
System
Integer DDC system
receives
Alarm Delay 104 Time delay before alarm activates Host DDC system must
divide value by 10 to report
alarm delay correctly.
Averaging Index 105 Display averaging period 0 .75 sec. 4 5 sec.
1 1 sec. 5 10 sec.
2 2 sec. 6 20 sec.
3 3 sec. 7 40 sec.
Units 106 Current pressure units displayed 0 Feet per minute
1 meters per second
2 inches of H2O
3 Pascal
4 millimeters H2O
Audible Alarm 107 Audible alarm indication 0 Off
1 On
Mute Delay 108 Length of time alarm is muted
when mute key is pressed
Host DDC system must
divide value by 600 to
report mute delay correctly.
Set Code Enable 113 Setpoint menu access code enable 0 Off
1 On
Alarm Code
Enable
114 Alarm menu access code enable 0 Off
1 On
Configure igure
Code Enable
115 Configure menu access code
enable.
0 Off
1 On
Cal Code Enable 116 Calibration menu access code
enable.
0 Off
1 On
Control Code
Enable
117 Control menu access code enable. 0 Off
1 On
System Code
Enable
118 System menu access code enable. 0 Off
1 On
Flow Code
Enable
119 Flow menu access code enable. 0 Off
1 On
Diag Code Enable 120 Diagnostic menu access code
enable.
0 Off
1 On
Inter Code Enable 121 Interface menu access code
enable
0 Off
1 On
Hood Code
Enable
122 Hood menu access code enable 0 Off
1 On
Exh Code Enable 123 Exhaust menu access code enable 0 Off
1 On