Omega CN8501 User guide

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User’s Guide

CN8500 Series

1/16 DIN Temperature and Process

Controllers

OMEGAnet®On-Line Service Internet e-mail

www.omega.com [email protected]

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The information contained in this document is believed to be correct, but OMEGA Engineering, Inc. accepts no liability for any errors it contains, and
reserves the right to alter specifications without notice.
WARNING: These products are not designed for use in, and should not be used for, patient-connected applications.

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Table of
Contents

Installation

Mounting 2
Contact Identification 3
Sensor Input Connections 4
Power Wiring 5

Operation

Notes on Outputs 6
Notes on Alarms 13
Parameter Menu Organization

and Descriptions

16

Tuning Procedures 20

Options

Auto/Manual 26
Remote Setpoint Select 26
Recorder Output (PV retransmission) 28
Transducer Excitation 29

Digital Communications 30
Recalibration Procedure 37
Error Codes 37
Technical Specifications 38
Ordering Codes 42
Warranty Information 44

1

The OMEGA®CN8500 Temperature and
Process Controller features:

 Omega LogicTM(allows selection of various cooling and

damping settings relative to single and multi-lag

processes and storage effects)

 Single input, RTD, thermocouple, current and voltage

input models available

 Voltage and current models scalable from -1999 to 9999

 Non-volatile memory

 NEMA 4X front panel

 Adjustable hysteresis and heat-cool spread

 User-selectable control modes (PID, PI, PD, and On/Off)

 User-selectable ramp to setpoint

 Auto-tuning, heat or cool

 Dual output and alarm capability

 RS-232 and RS-485 communications

 Twin-branched double wipe contacts

 Rugged molded housing with barriers and locking

terminals

 100 mm depth behind panel

 Wide range power supply: 100 to 250 Vac and 100 to

330 Vdc; 24 Vac/Vdc optional

Features

2

Figure 2. Case Dimensions

Prior to mounting the CN8500 Series in your panel, make sure
that the cutout opening is of the right size, 1.771" x 1.771"
(45 mm x 45 mm), and deburred to enable a smooth fit.
A minimum of 4" (100 mm) of depth behind the panel is required.

Figure 3. CN8500 Series Mechanical Components

Bezel

Case Clip

Grips

Rubber Gasket

Customer Panel

Installation

Figure 1. Recommended Panel Layout for Multiple
Controllers

Measurements between
centerlines of panel
cutouts
are minimum
recommended.

C

L

C

L

C

L

C

L

2.850" (72.4 mm)

2.150" (54.6 mm)

1.171" (45 mm)

3

Mounting

Notes on Wiring

Slide the mounting collar off and remove any wrapping
material from the instrument. (To ease removal of the collar,
gently pry up all three tabs on each side with a thin-blade screw­driver.)

slide the mounting collar back onto the unit from behind the
panel. Press the tabs of the mounting collar into the ridges of
the case housing. The case should now be secure in the cutout.
If it can still be moved, reposition the mounting collar until the
unit is completely immobile within the panel.

If it is necessary to remove the CN8500 Series chassis from the
case housing, press the grips on each side of the front panel
bezel firmly until the tabs release. The chassis may then be
pulled out. To re-install, press both bezel grips simultaneously
and carefully push the chassis back into the case housing until
the tabs snap into place.

IMPORTANT: All electrical wiring connections should be made
only by trained personnel, and in strict accordance with the
National Electrical Code and local regulations.

Power and signal wires should always be kept separate and
input leads should never be placed in the same conduit as power
leads. We recommend separating connecting wires into bundles:
power, signal, alarms and outputs. These
bundles should then be routed through individual conduits.
Shielded sensor cables should always be terminated at panel
ground.

If additional RFI attenuation is required, noise suppression
devices such as an R.C. snubber at the external noise source
may be used.

Figure 4. Contact Identification

4

Sensor Input
Connections

Figure 5. Thermocouple Input Wiring

Make sure that you are using the
appropriate thermocouple and
extension wire. Connect the neg­ative lead (generally colored red
in ISA-type thermocouples) to
contact #9; connect the positive
lead to contact #10. Extension wires must be the same
polarity as the thermocouple.

Figure 6. RTD Wiring

The CN8500 Series accepts
input from 2- or 3-wire, 100
ohm platinum resistance tem­perature detectors (RTDs).
Connect 2-wire RTDs to con­tacts #9 and #10, with a
jumper across contacts #8
and #9. Keep leads short and
use heavy gauge copper
extension wire, if necessary, to minimize lead resistance. For
long runs, 3-wire RTDs should be used.

Thermocouple circuit
resistance should not
exceed 100 ohms for
rated accuracy; errors
will occur at higher
resistance values. If
shielded thermocouple
wire is used, terminate
the shield only at panel
ground.

Use wire with a resis­tance no greater than
10 ohms. An error of

0.2° F will result for
each additional 10
ohms of resistance
encountered. If shield­ed RTD wire is used,
terminate the shield
only at panel ground.

Note: For 2 Wire RTD

Jumper 8 & 9

5

Power Wiring

Figure 7. Process and Linear Input Wiring

Voltage Inputs: Connect the
positive voltage input to con­tact #10; the negative input to
contact #8.
mV/Current Inputs: Connect
the positive current input to
contact #10; the negative
input to #9.

The CN8500 Series power supply accepts 100 to 250 Vac,
100 to 330 Vdc, or 24 Vac/Vdc line power without any switch
settings or polarity considerations. All connections should be
made in accordance with the National Electrical Code and
local regulations, using only NEC Class 1 wiring for all power
terminals.

It is advisable, but not necessary, to fuse one leg of the
incoming power line, contact #11, with a 2AG, 0.5 amp
rated fuse. Be sure that only instrument power input is

fused — not power to the load.

100 - 250 Vac 50/60 HZ
100 - 330 Vdc (Auto Polarity)
24 Vac/Vdc (Auto Polarity)

Figure 8. Power
Wiring
Connection

6

Operation

Omega CN8500 Series Universal Controller

The CN8500 Series is a full-function, autotuning PID con­troller, calibrated and pre-configured for your application
requirements, according to the ordering code specified, either
as a temperature or linear process controller.

Just a few easy steps are required before the instrument can
be placed into service. After completing the mounting and
wiring procedures as previously instructed, set your individ­ual process parameter values by stepping through the
CN8500 Series’ setup menus, using the simple front-panel
keys as instructed. Then, initiate the autotuning sequence as
shown (or tune manually).

Notes on Outputs

When you ordered your CN8500 Series controller, a specific
output type was specified, designated as either “R1,R2”, “F1,
F2”, “DC1,DC2”, or “T1,T2”. If you ordered the dual-output
CN8502 model, you also had the option of configuring your
controller with either one or two output actions. Generally,
output 1 is a heat (reverse-acting) function and output 2 is a
cool (direct-acting) function. For best results, follow the
recommendations for setting cycle times for the output type
supplied with your controller. A brief description of output
types follows:

Output Type Description

R 5A/3A (120/240 Vac) relay, normally

open, used for switching resistive loads. If
relays or solenoids are to be driven, select
the “T” output.

F 4-20 mA, full output to load with 500 ohm

impedance max. (suppressed).

DC 20 Vdc pulsed output for solid-state relays.

T1 A @ 120/240 Vac , solid-state relay, zero

voltage-switched and optically isolated from
drive signal. Only resistive loads to
may be controlled directly. Larger loads
may be controlled using an external
contactor.

7

Operation

Mode Key Used to access Standby,
Tune, Run or Manual modes.

Lower Key Used to scroll down through
available parameter settings, decrease values
or change menu levels (Hold for fast-step
progression)

Raise Key Used to scroll up through available
parameter settings, increase values or change menu
levels (Hold for fast-step progression)

Parameter/Access Key Used to index through parameters
or to access Menu Levels

After mounting and wiring your
CN8500 Series controller, you are
ready to set the parameter values
required of your application. Take
a moment to familiarize yourself
with the unit’s front panel con­trols and indicators.

Process Value

Displays measured
process temperature
in °F or °C or process
value in engineering
units

Setpoint Value

Displays programmed
setpoint temperature
in °F or °C or setpoint
value in engineering
units

Output 1

LED indication
of Heat cycle
(Output 1 action)

Output 2

LED indication
of Cool cycle
(Output 2 action)

Alarm 1

LED indication
of Alarm1 condition

Alarm 2

LED indication
of Alarm 2 condition

Function 1

LED indication of
Special Function 1

Function 2

LED indication of
Special Function 2

Figure 9. Front Panel Controls and Indicators

8

Operation

Power On

When power is first applied to the CN8500 controller, all LED
segments and indicators are momentarily illuminated. The
Process Value (PV) window then displays [ -At- ] or
[ -Ap- ] and the Setpoint Value (SV) window displays an ini­tialization code, e.g., [ tf06 ]. The last two digits of this code
indicate the software revision supplied with your controller.
Please provide this revision number when contacting us
regarding your controller. Depending upon whether Setpoint
Target Time [ SP.tt ] is enabled, you may also see this symbol:

or . This means that the controller is ramping up or
down to setpoint according to its previously programmed
parameters. The default setpoint on initial power up is equal
to the process value. Before proceeding further, wait until the
display has stabilized and then use the Raise or Lower

keys to enter or adjust your desired Setpoint Value.

Parameter Menu Organization

Your CN8500 Series controller has five distinct menu levels.
This enables quick access to relevant parameters without the
need for scrolling through long menus. Menu “05” is used for

9

Operation

initial controller configuration and menus “02” and “03” are
used for setting or changing parameters. Menus “00” and
“01” are used when the controller is in regular unattended
operation and are not used for setting parameters. For safety

and security purposes, we recommend placing the con­troller in menu level “00” or “01” when in regular opera­tion; however, it is not required.

If you wish to “escape” from parameter selection within
these menus at any time, simply press the Mode key
once. A description of the menu hierarchy and a detailed list­ing of menus and parameters begins on page 22.

Standby Mode

When the controller is placed in Standby Mode, outputs are
disabled; however, access is permitted to all menu levels and,
unless the controller is at Run menu levels “00” or “01”,
operating parameters may still be changed. Use this mode for
tuning the controller. To enter Standby Mode, press and hold
the Mode key for four seconds until the lower window
display flashes [ StbY ]. To exit Standby Mode from Menu
Levels “01” to “05”, press and hold the Mode key for four
seconds until the lower window display flashes [ tUnE ].
(If the Damping setting in menu “02” is [ OFF ], then [HEAt ]
or [ Cool ] will be displayed instead of [ tUnE ]. Press and
hold the Mode key for four more seconds until the lower
window returns to a steady display of Setpoint Value.

You cannot enter
Standby Mode from
menu level “00”.
Follow the instructions
for changing menu
levels to select another
level.

10

(This procedure will not affect tuning). Removing power to
the controller will also take the instrument out of Standby
Mode.

Accessing Menu Levels

To access menu levels from Standby Mode from menu
levels “02” to “05”, press the Parameter/Access key
once. From menu levels “00” and “01”, press and hold the
Parameter/Access key for approximately 11 seconds
until the lower window display alternates between [ Ac.Cd ]
and the menu level number last activated.

Changing or Displaying
Menu Levels

To change menu levels, access the menu level display as
instructed in the previous paragraph, then use the Raise
or Lower key to set the desired menu level number. To
display the current menu level setting in menu levels “02” to
“05”, from Standby or while adjusting/viewing parameters,
press the Parameter/Access key once. For menu levels
“00” and “01”, press and hold the Parameter/Access key
for approximately 11 seconds.

Operation

11

Because the CN8500
controller’s initial
configuration affects
other menu levels, it
is important to set all
required parameters in
this menu first before
accessing other
menu levels.

Operation

Menu Level Descriptions

Menu “05” (Configuration Setup)

This is the menu level used for specifying initial configuration
parameters before the controller is placed in Run mode.

After changing the access code to “05” as instructed in the
previous paragraph, press the Parameter/Access key to
step through the various control parameters. Available para­meters will flash in the lower window display, alternating with
the current value for that parameter. To increase or decrease
the value, simply press the appropriate Raise or Lower

key, then press the key to step to the next parame-

ter. To exit the menu at any time, press the Mode key.

Note: When programming in menu level “05”, all outputs
are disabled; however, any active alarms will remain active
until the alarm condition is removed. New alarm conditions
will not be recognized.

Menu “04” (Communications and Calibration Setup)

This menu is used to set up the controller for digital
communications and for recalibrating the controller. If your
CN8500 Series controller was ordered with the digital com­munications option, set these parameters next. To access this
menu level, follow the instructions previously given.

12

Operation

Menu “03” (Alarm, Timing and Limit Setup)

In this menu, alarms, cycle times, setpoint target time and
limits are established. After changing the access code to “03”,
press the Parameter/Access key to step through the vari­ous parameters. To set or change parameter values, follow
the instructions given previously.

Menu “02” (Control)

Gain, Rate and Reset parameters are automatically set during
autotuning. However, they can be manually adjusted by the
operator. To return the controller to the Run mode, change
the menu level access code back to “00” or “01” as previous­ly shown.

Menu “01” (Run — Limited Access Mode)

The only parameter that can be changed at this menu level is
the Setpoint Value, using the appropriate Raise or Lower

key. To set or change other parameters, the operator
must access another menu level by pressing and holding the
Parameter/Access key for 11 seconds.

Menu “00” (Run — “Key Lock” Lockout Mode)

This menu is automatically active when power is first applied.
Both display windows are illuminated; however, access is
denied to all parameters. To set or change parameters,
the operator must access another menu level as instructed
previously.

13

Operation

Notes on Alarms

Either [ OUT 1 ] or [OUT 2 ] in menu level “05” (but not both)
may be configured as an alarm [ ALr ] if your CN8502 con­troller was ordered with an “R”, “DC” or “T” type of output
module. When one of the two available Outputs is configured
as an alarm, the other Output may be used for control .

When the controller is provided with the Dual Alarm option,
two independent alarms are automatically enabled for both
outputs. DO NOT USE THE [ ALr ] SETTINGS FOR [ OUT 1 ]
OR [ OUT 2 ]. Otherwise, follow the regular instructions for
configuring the Dual Alarms in menu level “05”.

The dual-output CN8502 offers a unique capability that pro­vides for the activation of two software alarms (in addition to
the dual alarms) to monitor a total of four possible alarm con­ditions. To enable these software alarms, set the [ OUT 1 ] and
[ OUT 2 ] parameter(s) in menu level “05” to on/off mode
[ Ht.O ], [ CL.O ] or [ On.F ]. Set the Setpoint Value to your
first alarm point. Switch to menu level “02” and set Spread
[ C.Spr ] or [ Spr.2 ] to the desired deviation value from the
first alarm point. Set [H.HYS] and [C.HYS] to 1. Then switch
to menu level “03” and set the desired values for the third and
fourth alarm points at [ ALr 1 ] and [ ALr 2 ], respectively.
Press the Mode key to resume operation.

14

Operation

Available Alarm Types [ A1.P.d. ] [ A2.P.d. ]

Selectable at menu level “05”, as either Process [ Pr ] or
Deviation [ dE ] and either high or low [ A1.HL ] or [ A2.HL ].

Process Alarm: Activates at preset value independent of
setpoint. “High” process alarm activates at and above alarm
setting. “Low” process alarm activates at and below alarm
setting.

Deviation Alarm: Activates at a preset deviation value from
setpoint. “High” or “Low” deviation alarm activates above or
below setpoint according to the preset deviation value.

Latching Alarms

The CN8500 Series’s alarms may also be configured as latch­ing alarms by selecting “LAt” in the [ A1.O.P.] or [ A2.O.P.]
parameter selection at menu level “05”.

When a latching alarm
has been activated and
the alarm condition
has been removed, the
Mode key must be
pressed to unlatch the
alarm.

15

Figure 10. CN8500 Series Controller Menu Hierarchy

= temperature

controller only

= process

controller only

= temperature and

process controller

(All access denied)

16

Note: Menu parame­ters shown in regular
typeface appear only
for temperature
input types; menu
parameters in bold­face are for linear/
process input types.

Parameter
Descriptions

CN8500 Series Temperature/Process Controller

Menu “05”
Display Parameter Selection Code

SnSr Sensor type Thermocouple:

K c.A
JJ
Nn
Rr
Tt
SS
Platinel II PLII
RTD P (1 deg. resolution)

RTD (decimal range) d (0.1 deg. resolution)
FILt Digital Filtering 0.1-10.0
OUt1 Output 1 action Heat PID Ht.P

Heat On/Off Ht.O

Alarm ALr
OUt2 Output 2 action Cool PID CL.P

Cool On/Off CL.O

Alarm ALr

SN.00 Input Zero Level (0-20mA) U.Su (Unsuppressed)

(4-20mA) Su (Suppressed)
Dec.P Decimal Point 999, 99.9, 9.99
FILt Digital Filtering 0.1-10.0
OUt1 Output 1 action PID Pid

On/Off On.F

Alarm ALr
OUt2 Output 2 action PID Pid

On/Off ON.F

Alarm ALr

The Digital Filtering
setting [ FILt ] on the
CN8500 Series
controller allows the
operator to compen­sate for noise which
may cause the last
digits of the PV dis­play to become unsta­ble. Sampling rate is
not affected. The set­tings are time con­stants, in seconds,
with 0.1 equivalent to
“no filtering.”

17

CoL.t* Cooling type Water H2o (non-linear output)

Normal nor (linear output)
A1.H.L. Alarm 1 select Enable Lo/HI
A1.P.d. Alarm 1 type Process/Deviation Pr/dE
A1.O.P. Alarm 1 output Off/Normal/Latching OFF/nor/LAt
A2.H.L. Alarm 2 select Enable Lo/HI
A2.P.d. Alarm 2 type Process/Deviation Pr/dE
A2.O.P. Alarm 2 output Off/Normal/Latching OFF/nor/LAt
Unlt Measurement units °F or °C F/C

* For water-cooled extruders, select H2o.

Menu “04”
Display Parameter Allowable Values

Id.no Device ID number 00 to 99

(remote communications)

bAUd Baud, parity and See chart below

data bit selection
CAL.L Calibration low Preset at factory
CAL.H Calibration high Preset at factory

Available Communications Settings

Display Description

Baud Rate Parity Data Bits Stop Bits

3.o.7 300 odd 7 2

6.o.7 600 odd 7 2

12.o.7 1200 odd 7 2

24.o.7 2400 odd 7 2

3.n.8 300 none 8 1

6.n.8 600 none 8 1

12.n.8 1200 none 8 1

24.n.8 2400 none 8 1

Parameter
Descriptions

18

Parameter
Descriptions

Menu “03”
Display Parameter Allowable Values

ALr1 Alarm 1 preset Dependent on sensor range
ALr2 Alarm 2 preset Dependent on sensor range

(if ordered)
CY.t1 Cycle time output 1 00 to 120 seconds
CY.t2 Cycle time output 2 00 to 120 seconds
SP.tt Setpoint target time Off/1 to 100 minutes

(ramp-to-setpoint)
L.SP.L Lower setpoint limit Dependent on sensor range
U.SP.L Upper setpoint limit Dependent on sensor range

L.SCL Low scale setting -1999 to 9999
H.SCL High scale setting -1999 to 9999

Output Type Recommended Setting
(seconds)

R (5A/3A) 15 to 120
F (4-20 mA) MUST be set to 00
DC (pulsed 20 Vdc) 00 to 120
T (S.S. relay) 15 to 120

Menu “02”
Display Parameter Allowable Values

Gn.o1 Gain Output 1 00 to 400

(PID heat gain)

When changing
thermocouple types,
be sure to check/adjust
upper and lower set­point limit values.

Note: Menu parame­ters shown in regular
typeface appear only
for temperature input
types; menu parame­ters in boldface are for
linear/ process input
types.

Setting output cycle
time to “00” initiates
a 200 ms timebase.

A cycle time setting is required for
smooth proportional action. Too long
a setting will cause proportional ripple;
too short will decrease relay contactor
life. Shorter cycle times may be used
when driving heater loads directly.

Notes on Setpoint Target Time: The [ SP.tt ] parameter allows the operator to enter a time delay for the

process to reach setpoint temperature (ramp to setpoint), from disabled [ OFF ] or 1 to 100 minutes. When
enabled, the ramp sequence starts on power-up. The ramp-to-setpoint feature will also be initiated whenever
a new setpoint target time is entered AND the Setpoint Value is 5° F or more from the current process tem­perature. In operation, the controller’s lower window display will flash or to indicate that it is
“ramping” up or down to setpoint. The Setpoint Value cannot be changed during this procedure. After it is
finished, the operator can adjust the setpoint temperature to the desired value.

While in ramp startup, the ramp-to-setpoint mode can be aborted and the controller returned to regular
operation by pressing the Parameter/Access key until parameters are displayed and then pressing the
Mode key once.

19

Parameter
Descriptions

Gr.o2 Gain Ratio Output 2 0.0 to 2.0

(PID cool gain ratio)
H.HYS Heat Hysteresis 01 to 100°
C.HYS Cool Hysteresis 01 to 100°

HYS1 Output 1 Hysteresis 1 to 100
units
HYS2 Output 2 Hysteresis 1 to 100 units
SPr.2 Spread Adjustment, Output 2 0 to 100 units

C.SPr Cool Spread 0 to 100°
rAtE PID rate 00 to 900 seconds
rSEt PID reset 00 to 3600 seconds
dPnG Damping (see notes) Lo, nL, Hi, Off

Setting Rate
(Derivative) or
Reset (Integral) to
[ 00 ] disables that
aspect of PID con­trol. The ratio for
non-zero settings of
rate-to-reset is limit­ed to a minimum of
1:4, i.e., Reset value
cannot be set any
lower than four
times Rate.

The parameters of
Heat Hysteresis,
Cool Hysteresis and
Cool Spread are
only available when
Output 1 and/or
Output 2 are set to
on/off mode [Ht.O]
or [CL.O]. They
replace Gain Output
1 and
Gain Ratio Output
2, respectively.

Note: Menu parameters
shown in regular type­face appear only for
temperature input
types; menu parame­ters in boldface are for
linear/ process input
types.

Notes on Damping: The damping parameter is an autotune feature that enables more
precise control of setpoint overshoot during recovery from process upsets in which
thermal or transfer lag is a factor. See Figure 12. Use the correct setting prior to auto­tuning to compensate for power and load/sensor coupling characteristics.

Lo = Fast recovery with slight overshoot. For single-lag processes.

Ex. Adequate power and excellent load/sensor coupling.

nL = Normal recovery with no overshoot. For two-lag processes.

Ex. Properly sized heaters or components and good load/sensor
coupling.

Hi = Slow recovery with no overshoot. For three-lag processes.

Ex. Overpowered with multiple lags. Poor load/sensor
coupling.

Off = Autotune disabled; manual output control.

(This value may
exceed 400 during
autotuning.)

20

Introduction

The CN8500 Series is an “on demand” autotuning controller
that automatically sets PID parameter values (Proportional
Band, Reset and Rate) before the process reaches setpoint. A
damping setting (menu level “02”) MUST be selected for auto­tuning to take place The controller may also be tuned manually
(see page 31).

Autotuning the CN8500 Series Temperature
Controller

1) With the power off and the process at ambient, apply

power and immediately put the controller in Standby mode
by holding the key for four seconds until [ StbY ]
flashes in the lower display window.

2) Enter the desired Setpoint Value using the appropriate

Raise or Lower key. [ StbY ] will continue to flash.

3) If controller is in menu level “00” or “01”, hold the

Parameter/ Access key for 11 seconds until [ Ac.Cd ]
appears. Then change to menu level “05”. Otherwise, press
the key once and use the key to select menu level
“05”.

4) Press the Parameter/Access key twice until [ SnSr ] is

displayed to make sure that the proper sensor has been
selected. Then set the controller’s heating mode or alarm
functions by pressing the Parameter/Access key again

For best results in
tuning the temperature
controller, the setpoint
value should be at least
100°F above or below
ambient temperature.

While some processes
other than heat or cool
applications may
respond successfully to
autotuning procedures,
the controller must be
manually tuned for
most non-temperature
processes.

Figure 11. Typical Lag Processes

Flow

Tuning
Procedures

Immersion Heater

Lag

a. Single Lag

Flow

b. Two Lag

Flow

c. Three Lag

T/C2

Tank Wall =
Thermal Resistance

Thermal
Resistance

Thermal
Capacity

T/C1

Strip Heater

Strip Heater

a

. Single Lag with

1

Dead Time

T/C

Thermocouple

in Well

21

Tuning
Procedures

until [ OUt1 ] is displayed. (If you scroll past it, just

continue scrolling until the parameter menu repeats.) Using the
appropriate Raise or Lower key, select the one of the
following settings according to the requirements of your
process. Note: For autotuning, at least one output MUST be

set to PID mode.

Mode Output 1 (Heat) Setting

Output 2 (Cool) Setting
PID [ Ht.P ] [ CL.P ]
On/Off [ Ht.O ] [ CL.O ]
Alarm [ ALr ] [ ALr ]

Press the Parameter/Access key again to step to output 2 [
OUt2 ]. Repeat the selection process for cooling mode or alarm.

(If only one output is PID, set the other output to either On/Off
or Alarm.)

5) Press the Parameter/Access key again to display the

Cooling Type parameter [ CoL.t ], and select either
Normal/Linear output [ nor ] or Water-Cooled/Non-Linear output
[ H2o ].

6) Exit menu level “05” by pressing the Mode key once. The

lower window will flash [StbY]. Now press the
Parameter/Access key once. The lower window will
display [Ac.Cd ] and [ 05 ]. Press the Lower key twice
to select menu level “03”.

7) Press the Parameter/Access key and select Cycle Time for

Output 1 [ CY.t1 ] and Cycle Time for Output 2 [ CY.t2 ]. For
Control Output type R or T, enter “15”. For Control Output type F
or DC, enter “00”.

8) Press the Parameter/Access key until Setpoint Target Time

[ SP.tt ] is displayed. Select [ OFF ].

9) Press the Mode key once. The lower window will again

flash [StbY]. Press the Parameter/Access key once and the
lower window will display [Ac.Cd ] and [ 03 ]. Press the Lower

key once to select menu level “02”.

10) Press the Parameter/Access key and scroll through

the displayed parameters. If Gain Ratio [ Gr.o2 ] is displayed,
set it to [ 1.0 ]. Otherwise, continue scrolling until [dPnG ]
appears. Set Damping initially to Normal [ nL ]. (This setting
may have to be changed later. See Notes on Damping, page

26).

22

Before autotuning can
take place, you must
select a damping
setting. If the damping
parameter does not
appear on the menu,
you have not selected a
PID option for outputs
1 or 2. Refer back to
step (4) and select the
proper setting(s).

During autotuning, the
process temperature
will gradually cycle
from ambient to set­point. When autotuning
is complete, the [ tUnE ]
display will stop flash­ing and the Gain, Rate
and Reset numbers
"learned" will be kept in
memory for subsequent
startups.

Tuning Procedures

11) Press and hold the Mode key until [ tUnE ] flashes
in the lower display window. The controller is now autotun­ing. When it stops flashing, the autotuning procedure is
completed and the controller is ready for your process.
As a security measure, you may wish to place the controller
in Key Lock “00” or Limited Access “01” Run mode by
changing menu levels as instructed previously.

Note: Re-tune controller only from ambient temperature.

Autotuning will not function when process is at setpoint.

Figure 12. Typical
“Autotune”
Temperature Profile.

23

If overcooling exists on
heat/cool processes
after autotuning,
decrease Gain Ratio
[ Gr.o2 ] in steps of 0.1
until oscillation is
minimal. If cooling is
sluggish, increase the
value in steps of 0.1
until optimum results
are achieved.

Gain ratio [ Gr.o2 ] is
the cooling gain
expressed as a factor
of the heating gain.

Ex. [ Gn.01 ] = 100

Cooling Gain = 50
[ Gr.o2 ] = .5

Tuning
Procedures

Manual Tuning Procedure - Temperature
Controller (Zeigler-Nichols PID Method)

This tuning method may be used if the spread between ambi­ent temperature and process operating temperature is small.
For best results, the use of a recording device is suggested
when tuning with this method.

1) Disable any cooling device used.

2) Apply power and place the controller in Standby by

pressing and holding the Mode key for four seconds.

3) Using Raise or Lower key, adjust setpoint to

desired value.

4) Access menu level “02” following instructions given

previously.

5) Using the Parameter/Access key, index to Heat Gain

[ Gn.o1 ]. Select [ 01 ].

6) Index to Gain Ratio [ Gr.o2 ] and select [ 1.0 ].

7) Index to Rate [ rAtE ] and select [ 00 ].

8) Index to Reset [ rSEt ] and select [ 00 ]. Note: In order to

set Reset to [ 00 ] , Rate must first be set to [ 00 ].

9) Change to menu level “03”.

10) Index to Cycle Time 1 [ CY.t1 ] and select the timebase,

in seconds, appropriate to the device being controlled.

24

Tuning
Procedures

11) Repeat for Cycle Time 2 [ CY.t2 ].

12) Change to menu level “05”.

13) Set Cooling Type [ CoL.t ] to [ nor ].

14) Press the Mode key once. Setpoint Value will be

displayed. The recording device should now be tracking
process temperature.

15) Double the Gain [ Gn.o1 ] until a small, sustained oscilla-

tion is visible on the recording device’s trace.

16) Measure the period of one cycle of oscillation (“T” on the

diagram below).

17) Divide the period of oscillation (T) by eight (8). The

resulting number is the correct Rate time [ rAtE ] in sec­onds. Multiply this number by four. This is the correct
Reset time [ rSEt ] in seconds.

18) Multiply the gain (from step #15) by 0.6 and enter this

number as Gain [ Gn.o1 ].

19) Enable the cooling device. If overcooling exists, decrease

the Gain Ratio [ Gr.o2 ] in steps of 0.1 until temperature
oscillation stops. If cooling is sluggish, increase the Gain
Ratio in steps of 0.1 until optimum results are achieved.

T

25

Tuning
Procedures

Manual Tuning Procedure - Process Controller
(Zeigler-Nichols PID Method)

A chart recorder to monitor the process variable is required. The
controller must be properly scaled and filtering set as instructed
previously.

1) Apply power and place the controller in Standby by holding

the Mode key for four seconds.

2) Adjust the setpoint to the desired value.

3) Access menu level “05” and select one output: [ OUt 1 ]

for reverse-acting control or [ OUt 2 ] for direct-acting
control. Set the active output to PID [ Pid ] and the unused
output to Alarm [ ALr ] or On/Off [ On.F ].

4) Access menu level “02” and set [ Gn.01 ] to 1.0; [ Gr.o2 ] to

1.0; and [ rAtE ] and [ rSEt ] to “00”.

5) Press the Mode key for four seconds until display

flashes [ tUnE ]. Press the Mode key for another four sec­onds and the process will run in closed loop mode.

6) While monitoring the chart, increase Gain [ Gn.o1 ] by dou-

bling the gain number until the process variable becomes
unstable. Then decrease Gain until the process oscillations
are sustained, neither increasing nor decreasing in amplitude
as a result of momentary setpoint change.

7) Multiply the Gain from Step (6) by 0.6.

8) Measure the period of one complete cycle of oscillation,

“T”, in seconds.

Calculate and enter these
numbers:

Rate [ rAtE ] = T/8
Reset [ rSEt ] = T/2
Gain [ Gn.01 ] = Gain from

Step (6)

On noisy processes,
where Rate cannot be
used:

Gain [ Gn.01 ] = from Step

(6) x 0.45

Reset [ rSEt ] = T/1.2

T

26

Auto/Manual Operation (Standard)

To put the controller in manual mode, set the damping [dPnG]
parameter in menu level “02” to [ OFF ]. Press and hold the
Mode key for four seconds until the lower display win­dow flashes [ StbY ]. Hold down the Mode key for another
four seconds to initiate manual operation. The lower display
window will flash percentage of output power, from 100 to

-100, alternating with the output controlled (temperature
controllers will flash [ HEAt ] or [ CooL], process controllers
will flash [ OUt1 ] or [OUt2 ].) To take the controller out of
manual mode, press and hold Mode key to four seconds.

Note: The CN8500 Series controller can be ordered with
only one

of the following options installed per instrument.

These options cannot be field-installed.

Remote Setpoint Select

If your CN8500 Series controller was ordered with this option,
you may select either of two setpoints for your process. The
second setpoint can be enabled only by an external switch or
signal, according to your ordering specifications. The "F2"
LED on the front panel will illuminate when a second setpoint
is selected.

Options

In manual control
mode, error conditions
such as A/D errors
and open or reversed
sensors will be
ignored.

27

Options

Option Part # Description

-RSP1 External switch wired to terminals 6 and 7
Switch Open: Normal operation, first setpoint enabled
Switch Closed: Second setpoint enabled
Setpoint Adjustments: Made from front panel

-RSP2 External switch wired to terminals 6 and 7
Switch Closed: Normal operation, first setpoint enabled
Switch Open: Second setpoint enabled
Setpoint Adjustments: Made from front panel

-RSP3 0-5 Vdc signal at pins 6 and 7
0 Vdc: First setpoint enabled
5 Vdc: Second setpoint enabled
Setpoint Adjustments: Made from front panel

Maximum Input Impedance: 400 ohms @ +5 Vdc , 5 mA

Figure 13. Wiring
Diagram for
Remote Setpoint
Select Option

28

Options

Recorder Output (PV transmission)

If your CN8500 Series controller was ordered with this option,
you may retransmit the signal representing the process vari­able for analysis or storage to an external device that accepts
analog input, such as a chart recorder, datalogger, or process
control computer. These outputs are:

Suppressed: 1-5 Vdc/4-20 mAdc

Unsuppressed: 0-5 Vdc/0-20 mAdc

Ordering Suffix: -PV1 = 4 to 20 mA

-PV2 = 0 to 5 Vdc

I

out

(current output) = 0-20 mA/4-20 mA

Voltage Headroom = 8 Vdc (standard) ; 18 Vdc (for

multiple recording devices)

V

out

(voltage output) = 0-5Vdc/1-5 Vdc

I

out

Max = 20 mA

These output values
are linear with and
dependent upon the
sensor being used,
i.e., the lowest value
of the sensor’s out­put range corre­sponds to zero or
low for the output
function.

For voltage output, a
jumper must be
installed between
terminals 13 and 14.

Figure 14. Wiring
Diagram for
Process Variable
Retransmission

29

Options

Transducer Excitation

The transducer excitation voltage option is used to produce
a constant dc voltage of Vdc out to an external device, elimi­nating the need for an additional external power supply.

Maximum Current: 22 mA
Output Voltage: 15 Vdc
Ambient Temperature: 0 to 55° C (32 to 131° F )

Ordering Suffix: -XP1

Figure 15. Wiring Diagram for Transducer Excitation

30

Two communication
options are available
for the CN8500 Series
which allow interfacing
to remote devices uti­lizing the most common
industry standards,
RS232 and RS485.

WARNING

Signal ground only.
Grounding to frame
may damage the
controller and void
warranty.

Digital
Communications

RS232

This method allows bidirectional data transfer via a three­conductor cable consisting of signal ground, receive input
and transmit output. It is recommended for communication
distances less than fifty feet between the computer terminal
and the instrument. Note: Multiple instruments cannot be
connected to the same port.

The RS232 port is optically isolated to eliminate ground loop
problems. Typically, “Data Out” of the computer/terminal
connects to the “RCV” terminal. “Data In” connects to the
“XMT” terminal. If shielded cable is used, it should be
connected to the frame ground at one end only. Signal
ground is to be connected at appropriate ground terminals.

RS485

The RS485 multipoint capability allows up to 32 controllers to
be connected together in a half-duplex network or up to 100
controllers with an appropriate communications repeater. This
method allows bidirectional data transfer over a shielded
twisted pair cable. The twisted pair cable is a transmission
line; therefore, terminating resistors are required at the most
distant ends of the line to minimize reflections (typically 60
ohms from each line to signal ground). The RS485 circuit is
fully optically isolated, eliminating ground loop problems.
Parallel drops from the transmission lines should be kept as
short as possible; however, the line may be daisy-chained at

31

Digital
Communications

each controller. The polarity of the line is important and each
device will specify an “A” (+) and “B” (-) connection.

Figure 16. Wiring
diagram for digital
communications.

*One PC to
one controller
only

32

Digital
Communications

Table 1. Communications Parameter List
(Temperature Controller)

Parameter No. Description Display Minimum Maximum

00 Process Value nnnn Sensor Dependent
01 Setpoint nnnn Low Limit High Limit
02 Access Code Ac.Cd 00 05
03 Gain Output 1 Gn.o1 00 400
04 Gain Ratio 2 Gr.o2 0.0 2.0
05 Rate rAtE 00 900
06 Reset rSEt 00 3600
07 Heat Hysteresis H.HYS 01 100
08 Cool Hysteresis C.HYS 01 100
09 Cool Spread C.SPr 00 100
10 Damping dPnG 00 Low/Normal/High
11 Alarm 1 ALr1 Range Dependent
12 Alarm 2 ALr2 Range Dependent
13 Cycle Time 1 CY.t1 00 120
14 Cycle Time 2 CY.t2 00 120
15 Setpoint Target Time Sp.tt 00 (OFF) 100
16 Low Setpoint Limit L.SP.L Sensor Dependent
17 High Setpoint Limit U.SP.L Sensor Dependent
18 Controller ID Id.no 00 99
19 Baud Rate bAUd 300 2400

Table 2. Communications Parameter List
(Process Controller)

Parameter No. Description Display Minimum Maximum

00 Process Value nnnn Low Scale High Scale
01 Setpoint nnnn Low Scale High Scale
02 Access Code Ac.Cd 00 05

33

Digital
Communications

03 Gain Output 1 Gn.o1 00 400
04 Gain Ratio 2 Gr.o2 0.0 2.0
05 Rate rAtE 00 900
06 Reset rSEt 00 3600
07 Hysteresis 1 HYS.1 01 100
08 Hysteresis 2 HYS.2 01 100
09 Spread 2 SPr.2 00 100
10 Damping dPnG 00 Low/Normal/High
11 Alarm 1 ALr1 Low Scale High Scale
12 Alarm 2 ALr2 Low Scale High Scale
13 Cycle Time 1 CY.t1 00 120
14 Cycle Time 2 CY.t2 00 120
15 Setpoint Target Time Sp.tt 00 (OFF) 100
16 Low Scale L.SCL -1999 9999
17 High Scale H.SCL -1999 9999
18 Controller ID Id.no 00 99
19 Baud Rate bAUd 300 2400

Table 3. Serial Communications Data Format

Baud Baud Parity Data Stop
Code Rate Bits Bits
0 300 Odd 7 2
1 600 Odd 7 2
2 1200 Odd 7 2
3 2400 Odd 7 2
4 300 None 8 1
5 600 None 8 1
6 1200 None 8 1
7 2400 None 8 1

#[controller id] [command] [parameter number]<new value><units> [CR]

N ON

(Select)

F OFF

(Deselect)

?STATUS

0 Standby
1 Autotune
2 Manual
3 Ramp
9Version

(Status Only)

Caution:

Modifying parameter
#19 (Baud Rate) by
host may cause loss of
data link.

SAMPLE
BASIC Program:

10 OPEN “COM2: 2400, N, 8,

1, CS, DS” AS #1

20 PRINT “WHAT IS

COMMAND”,

30 INPUT A$
40 PRINT #1, A$
50 INPUT #1, B#
60 PRINT “THE RESPONSE

IS: “; B$

70 PRINT
80 GOTO 20
90 CLOSE

Start of

message

End of

message

Up to TWO

Numeric

Characters

00 to 99

Up to TWO

Numeric

Characters

00 to 99

Up to SIX

Characters

ONE Leading

Sign

‘-’,‘+’ or

Space and

FOUR

Numeric

Characters

with decimal

for decimal

parameters

OPTIONAL

OPTIONAL

ONE

Character

Upper case

or Lower case

R Read
M Modify
EEnter

ONE
Character
FDeg F

C Deg C
U PROCESS

SENSOR
None for default
Temperature units
or NON-THERMAL
parameters

SPECIAL

COMMANDS

Example: For Standby “On”, type #01N0[CR].

34

Digital
Communications

Interface Examples

This section describes the protocol for communication
between an CN8500 Series controller and either a video dis­play terminal or computer ( referred to below as “the host”).
Message strings may be of two types — commands to con­troller or responses from controller.

General Comments

One host and multiple controllers may be interconnected on a
single bus. The host may send commands to any controller
and may receive responses from any controller. Each con­troller on the bus is assigned an identification code between
00 and 99. No two controllers on a given bus may have the
same identification code. Controllers are not capable of com­municating with other controllers.

Every valid message begins with a pound-sign (#) character.

Every valid message ends with a carriage-return (<CR>)
character.

A valid message is composed of: Start Message, Controller ID
Code, Command, Parameter and Data.

Every response begins with a line-feed (<LF>) character and
ends with a carriage-return, line-feed pair (<CRLF>).

Figure 17. General Communications Message Format

Digital
Communications

READ MESSAGE TO CONTROLLER READ RESPONSE FROM CONTROLLER

MODIFY COMMAND TO CONTROLLER MODIFY RESPONSE FROM CONTROLLER

ENTER COMMAND TO CONTROLLER ENTER RESPONSE FROM CONTROLLER

‘#01R00<CR>’‘

<LF>

#01R00 = 0120F<CR><LF>’

Controller Id

Parameter Number

End of
Message

Read

Command

Start of Message

‘#01M01 0200F<CR>’

Controller Id

Parameter Number

Units

Value read from
controller

Units

End of

message

Start of Message

New Value

‘space’ for

Positive

Modify Command

‘#01E01 0200F<CR>’

Controller Id

Parameter Number

Units

End of

message

Start of Message

New Value

‘space’ for

Positive

Enter Command

‘<LF>#01M00 = 0200F<CR><LF>’

Modified Value

Units

‘<LF>#01E00 = 0200F<CR><LF>’

Entered Value

Units

SAMPLE: READ, MODIFY, ENTER COMMANDS

STANDBY ‘ON’ COMMAND TO CONTROLLER STANDBY RESPONSE FROM CONTROLLER

STANDBY ‘OFF’ COMMAND TO CONTROLLER STANDBY RESPONSE FROM CONTROLLER

STANDBY ‘?’ COMMAND TO CONTROLLER STANDBY RESPONSE FROM CONTROLLER

‘#01N0<CR

>

‘<LF>#01N0<CR><LF>’

Controller Id

STANDBY

End of
Message

ON (Select)

Command

Start of Message

‘#01F0<CR

>

Controller Id

STANDBY

End of
Message

Command
Executed

‘<LF>#01F0<CR><LF>’

Command
Executed

‘<LF>#01F0<CR><LF>’

Standby STATUS
is ‘off’
Standby STATUS
is ‘on’

OFF (Deselect)

Command

Start of Message

‘#01?0<CR

>

Controller Id

STANDBY

End of
Message

Status REQUEST

Command

Start of Message

N

Figure 18. Sample Communications Command

Figure 19. Requesting a Parameter from a Controller

35

36

Caution:

Wherever possible,
avoid using the
“Enter” command
and use “Modify” or
“Read” instead. The
“Enter” command
makes permanent
changes to the
NOVRAM in the
CN8500 Series’s
microprocessor, and
after accepting a
maximum capacity of
100,000 “Enter” state­ments, it will have to be
returned to the factory
and replaced.

Communications
Notes

1. The controller will respond with <LF>ERROR<CR><LF>

for messages containing invalid/incorrect commands,
parameter number or data (with decimal, if needed).

2. Process Value is a read-only parameter; therefore, a mod-

ify or enter command for Process Value will result in a
<LF>ERROR<CR><LF> response.

3. For modify or enter command: if the new value is out of

the parameter’s range, the controller will default to the
highest or lowest allowable parameter value.

4. Parameters with decimal data must contain a decimal

character in the data portion of the message.

5. Ramp “on” command (Setpoint Target Time) will not be

executed if ramp time is set to zero or absolute deviation
between Setpoint and Process Value is less than or
greater than 5 temperature or process units.

6. Autotune, manual and ramp commands are mutually

exclusive, i.e., selecting manual while autotune is enabled
will abort the autotune mode.

7. If the controller is in Standby mode, selecting autotune,

manual or ramp will de-select Standby.

8. Setpoint should not be modified while the controller is in

autotune or ramp mode.

9. The Setpoint Value enter command should not be execut-

ed while the controller is in manual mode.

37

Recalibration

Your CN8500 Series has been calibrated at the factory, and
need not be adjusted during the life of the controller unless
sensor type is changed from thermocouple to RTD, or vice
versa. In the event that recalibration is warranted, follow
these procedures.

1) Access menu level “05” as previously instructed and

select the sensor type.

2) Use a calibrator with a range appropriate for the unit to be

calibrated and set the range, and a low or zero value.

3) Access menu level “04” and then the Parameter/Access

key until [ CAL.L ] is displayed. Then, press the Raise

or Lower key until the number in the controller’s
upper (PV) display window matches the indicated value of
the calibration instrument.

4) Enter a value on the calibration instrument corresponding

with the high-end value of the sensor range (span).

5) Again, in menu level “04”, press the Parameter/Access

key until [ CAL.H ] is displayed. Then, press the Raise

or Lower key until the number in the controller’s
upper (PV) display window matches the indicated value of
the calibration instrument.

6) Repeat steps 3 through 5 until all readings agree.

7) Return the controller to regular operation by pressing the

Mode key.

Only qualified indi­viduals utilizing the
appropriate calibra­tion equipment
should attempt
recalibration of
the controller.

Error Codes

Display Problem Action

[ Err.H ] Open sensor Check sensor and wiring

Check type of sensor
Recalibrate

[ Err.L ] Reversed sensor Check sensor and wiring

Check type of sensor
Recalibrate

[ Err.O ] A/D error Return to factory

[ Err.J ] A/D error Return to factory

- - - - Display out-of-range Sensor over- or under-range

38

Performance

Accuracy ±0.2% of full scale, ± one digit
Setpoint Accuracy 1 °/0.1°
Temperature Stability 5 µV/°C max; 3 µV/°C typical
TC Cold End Tracking 0.05° C/°C ambient
Noise Rejection Common mode >100 dB

Series Mode >70 dB

Process Sampling Rate 10 Hz (100 ms)

Input Types

Thermocouple 6 (K, J, N, R, T, S)

Maximum lead resistance 100 ohms
for rated accuracy

RTD Platinum 2- and 3-wire, 100 ohms at

0° C, DIN curve standard (0.00385)

DC Voltage 0-50 mV/10-50 mV, 0-5 V/1-5 V,

0-10V/2-10 V

DC Current 0-20 mA/4-20 mA

Input Impedances

0-50 mV/10-50 mV: 1 K ohm ± 1%
0-5/1-5 V: 100 K ohms ± 1%
0-20 mA/4-20 mA: 2.5 ohms ± 1%
0-10 V/2-10 V: 200 K ohms

Technical
Specifications

39

Input
Code Type Range Resolution

TC

RTD

V5

V10

MV

MA

K

CHROMEGA

®

-ALOMEGA

®

T

Copper-Constantan

J

Iron-Constantan

-18 to 760° C
0 to 1400° F

Input Ranges and Resolutions

N

OMEGALLOY

®

R

Pt/13%Rh-Pt

S

Pt/10%Rh-Pt

RTD

2, 3-wire, 100-ohm Pt

RTD

2, 3-wire, 100-ohm Pt

1 to 5 V
0 to 5 V

2 to 10 V
0 to 10 V

10 to 50 V

0 to 50 V

4 to 20 mA
0 to 20 mA

-129 to 316° C

-200 to 600° F

-18 to 1349° C
0 to 2460° F

-18 to 1299° C
0 to 2370° F

-18 to 1760° C
0 to 3200° F

-18 to 1760° C
0 to 3200° F

-200 to 850° C

-328 to 1562° F

-128.8 to 232.2° C

-199.0 to 450.0° F

Scalable (-1999 to +9999)
Scalable (-1999 to +9999)

Scalable (-1999 to +9999)
Scalable (-1999 to +9999)

Scalable (-1999 to +9999)
Scalable (-1999 to +9999)

Scalable (-1999 to +9999)
Scalable (-1999 to +9999)

1° C
1° F

1° C
1° F

1° C
1° F

1° C
1° F

1° C
1° F

1° C
1° F

1° C
1° F

0.1° C

0.1° F

Selectable
Selectable

Selectable
Selectable

Selectable
Selectable

Selectable
Selectable

40

Technical
Specifications

Outputs

#1 Reverse acting (heating) [alarm]
#2 (CN8502 only) Direct acting (cooling) [alarm]
R1, R2 Relay, 5 A @ 120 Vac resistive

3 A @ 240 Vac
F1, F2 4-20 mAdc, 500 ohms max.
DC1, DC2 20 Vdc pulsed
T1, T2 Solid-state relay, 120/240 Vac,

zero voltage-switched,

1 A continuous, 10 A surge @ 25° C

Alarms

Electromechanical relay, 5 A @ 120 Vac,

3 A @ 240 Vac (Output 1 OR 2 only)

Dual-Alarm option: Two solid-state

relays, 120/240 Vac, zero voltage-

switched, 1 A continuous, 10 A surge

@ 25°C

Control Characteristics

Setpoint Limits Limited to configured range
Alarms Adjustable for high/low; selectable

process or deviation
Rate 0 to 900 seconds
Reset 0 to 3600 seconds
Cycle Time 0.2 (zero setting) to 120 seconds
Gain 0 to 400
Gain Ratio 0 to 2.0 (in 0.1 increments)

41

Technical
Specifications

Control Hysteresis 1 to 100 units (on/off configuration)
Cool Spread, Output 2 0 to 100° F/C (above setpoint)
(Temperature Controller)
Spread 2, Output 2 0 to 100 units (above setpoint)
(Process Controller)
Damping Selectable (low, normal, high, off)
Setpoint Target Time 0 (off) to 100 minutes
(Ramp-to-Setpoint)
Autotune Operator-initiated from front panel
Manual Operator-initiated from front panel

General

Line Voltage 115 to 230 V ±10%, 50-60 Hz

115 to 300 Vdc ±10% (Auto-Polarity)

24 Vac/dc (optional)
Display Dual, 4-digit 0.36" (9.2 mm) LED display

Process Value: Orange

Setpoint Value/Menu: Green
Power Consumption Less than 6 VA (@ 120/240 Vac)
Weight < 8 oz (< 226.8 g)
Panel Cutout 1.771" x 1.771" (45 mm x 45 mm)
Depth Behind Panel 3.937" (100 mm)
Front Panel Rating NEMA 4X
Operating Temperature 32 to 131° F (0 to 55° C)
Humidity Conditions 90% R.H. max., non-condensing
Parameter Retention Solid-state, non-volatile memory
Connections Input and output via barrier strip

with locking terminals
Contacts Twin bifurcated

42

*Not available for voltage or
current input models (input
codes MV, V5, V10, or MA)

Ordering
Numbers

CN8500 Series
Ordering Number Description

CN8501 1/16 DIN Single

output controller

CN8502 1/16 DIN Dual

output controller

Output Type - Ordering Suffix

CN8501 CN8502

5 A relay -R1 -R2
1 A SSR -T1 -T2
4-20 mA -F1 -F2
20 Vdc pulse -DC1 -DC2

Options (cannot be field-installed)
Description Ordering Suffix

Dual alarms -A
RS-232 communications -C2
RS-485 communications -C4
4-20 mA recorder output -PV1*
0-5 Vdc recorder output -PV2*
Remote switch closed,

with one alarm -RSP1*

Remote switch open,

with one alarm -RSP2*

0 or 5 Vdc remote setpoint

with 1 alarm -RSP3*

Transducer power supply -XP1*

43

CN8500 Series Option Compatibility

When the following features are used together, connections to all but
one must float, i.e., no more than one in each group can be referenced
to any ground.

Group 1

Group 2
Transducer excitation Any input
F or DC output Analog setpoint
Communications Aux. output

(P.V. retransmit)

DC alarms (except floating transistor)
Digital input (remote setpoint select)
Aux. output

(P.V. retransmit)

Note: Auxiliary output (P.V. retransmit) and transducer

excitation cannot be used together in any configuration.

Ordering
Numbers

44

OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible.
This affords our customers the latest in technology and engineering.

OMEGA is a registered trademark of OMEGA ENGINEERING, INC.
© Copyright 2004 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied, repro-

duced, translated, or reduced to any electronic medium or machine-readable form, in whole or in part, without the prior
written consent of OMEGA ENGINEERING, INC.

WARRANTY/DISCLAIMER

OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship
for a period of 13 months from date of purchase. OMEGA’s Warranty adds an additional one (1)
month grace period to the normal one (1) year product warranty to cover handling and shipping
time. This ensures that OMEGA’s customers receive maximum coverage on each product.
If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer
Service Department will issue an Authorized Return (AR) number immediately upon phone or writ­ten request. Upon examination by OMEGA, if the unit is found to be defective, it will be repaired or
replaced at no charge. OMEGA’s WARRANTY does not apply to defects resulting from any action of
the purchaser, including but not limited to mishandling, improper interfacing, operation outside of
design limits, improper repair, or unauthorized modification. This WARRANTY is VOID if the unit
shows evidence of having been tampered with or shows evidence of having been damaged as a
result of excessive corrosion; or current, heat, moisture or vibration; improper specification; misap­plication; misuse or other operating conditions outside of OMEGA’s control. Components which
wear are not warranted, including but not limited to contact points, fuses, and triacs.

OMEGA is pleased to offer suggestions on the use of its various products. However,
OMEGA neither assumes responsibility for any omissions or errors nor assumes liability for any
damages that result from the use of its products in accordance with information provided by
OMEGA, either verbal or written. OMEGA warrants only that the parts
manufactured by it will be as specified and free of defects. OMEGA MAKES NO OTHER
WARRANTIES OR REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESS OR IMPLIED,
EXCEPT THAT OF TITLE, AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MER­CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. LIMITA­TION OF LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total liability
of OMEGA with respect to this order, whether based on contract, warranty, negligence, indemnifica­tion, strict liability or otherwise, shall not exceed the purchase price of the component upon which
liability is based. In no event shall OMEGA be liable for consequential, incidental or special dam­ages.

CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a
“Basic Component” under 10 CFR 21 (NRC), used in or with any nuclear installation or activity; or
(2) in medical applications or used on humans. Should any Product(s) be used in or with any
nuclear installation or activity, medical application, used on humans, or misused in any way,
OMEGA assumes no responsibility as set forth in our basic WARRANTY / DISCLAIMER language,
and, additionally, purchaser will indemnify OMEGA and hold OMEGA harmless from any liability or
damage whatsoever arising out of the use of the Product(s) in such a manner.

RETURN REQUESTS/INQUIRIES

Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department. BEFORE
RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST OBTAIN AN AUTHORIZED RETURN (AR)
NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID PROCESSING DELAYS).
The assigned AR number should then be marked on the outside of the return package and on any
correspondence.

The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent

FOR W

ARRANTY RETURNS, please have the follow­ing information available BEFORE
contacting OMEGA:

1. Purchase Order number under which

the product was PURCHASED,

2. Model and serial number of the product under

warranty, and

3. Repair instructions and/or specific

problems relative to the product.

FOR NON-WARRANTY REPAIRS,

consult OMEGA for
current repair charges. Have the following informa­tion available BEFORE
contacting OMEGA:

1. Purchase Order number to cover the

COST of the repair,

2. Model and serial number of the

product, and

3. Repair instructions and/or specific problems

relative to the product.

45

This document is based on information available at the time
of its publication. While efforts have been made to render
accuracy to its content, the information contained herein does
not cover all details or variations in hardware, nor does it
provide for every possible contingency in connection with
installation and maintenance. Features may be described
herein which are not present in all hardware. Controls
assumes no obligation of notice to holders of this document
with respect to changes subsequently made.

Proprietary information of Controls, Inc. is furnished for cus­tomer use only. No other use is authorized without the written
permission of Controls, Inc.

Repair
Information

RETURN REQUESTS / INQUIRIES

BEFORE RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST
OBTAIN AN AUTHORIZED RETURN (AR) NUMBER FROM OMEGA’S
CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID PROCESSING
DELAYS). The assigned AR number should then be marked on the outside of
the return package and on any correspondence.

OMEGA’s policy is to make running changes, not model changes, whenever
an improvement is possible. This affords our customers the latest in
technology and engineering.

OMEGA is a registered trademark of OMEGA ENGINEERING, INC.

© Copyright 2003 OMEGA ENGINEERING, INC. All rights reserved. This
documentation may not be copied, photocopied, reproduced, translated,
or reduced to any electronic medium or machine-readable form, in whole or
in part, without prior written consent of OMEGA ENGINEERING, INC.

46

Notes:

47

Notes:

48

Notes:

Where Do I Find Everything I Need for

Process Measurement and Control?

OMEGA…Of Course!

Shop online at www.omega.com

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✓

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M1508/0804