Watlow EHG CL User Manual

Series EHG CL

Integrated Temperature Controller

User’s Guide

The Series EHG CL is a powerful instrument that in­tegrates a temperature process controller, high-low tem­perature alert, and power switching with a safety high
limit that meets UL® 1998 and CE 60730 requirements.
The optional display and communications modules can
be easily upgraded in the field to provide a digital dis­play, adjustable control parameters, RS-485 MODBUS
communications and other interface features. The com­pact design, inherent reliability and integrated safety
limit functions make this control a tremendous value.
The control is designed for easy integration with Wat­low heaters providing additional value to simplify the
engineering and component count on new equipment.
CE compliance and UL recognition will reduce time and
costs necessary for global agency testing and validation
for OEMs.

Features

Standard Base Module

• Two, type K thermocouple inputs: process temperature
controller and safety limit

• Process temperature output: 10 amp “NO ARC” relay

• Safety limit: 10 amp relay

• On-off and PID temperature control algorithm: Up­graded via communications to PID algorithm (minimum
cycle time 5 seconds)

0600-0091-0000 Rev. A

September 2012

Integrated Temperature Control

• Standard Molex Connectors

• Dimensions

Configuration Width Depth Height

Basic unit 88.8 mm

Control with mounting
bracket

Control with communi­catons-display module &
mounting bracket

Optional Communications Module

• Field adjustable set point

• Access to PID parameters

• Modbus RTU Communications

• RS-485

• 3-character, 7-segment LED display

• User Interface Software
The Series EHG CL User’s Guide is copyrighted by

Watlow Winona, Inc., © September 2012, with all rights
reserved.

Patent Pending

1241 Bundy Boulevard

Phone: [phone]; Fax: [phone]

http://www.watlow.com

(3.496 in)

88.8 mm
(3.496 in)

88.8 mm
(3.496 in)

Watlow Winona

Winona, MN 55987

40.2 mm
(1.582 in)

48.4 mm
(1.907 in)

63.6 mm
(2.503)

55.8 mm
(2.196 in)

55.8 mm
(2.196 in)

55.8 mm
(2.196 in)

Navigating the Series EHG CL with the Front Panel

The three-character display normally shows the process
temperature. To view and change the existing Set Point
value follow the steps below:

1. Press the Mode Key once. The right decimal point

will illuminate when viewing the Set Point value.

2. Press the Up-Arrow or Down-Arrow Key to change

the Set Point.

3. Press the Mode Key again to return to the process

temperature display.

The display will automatically return to showing the
process temperature after three seconds.

To view or change parameter values follow the steps
below:

1. Hold down both the Up-Arrow and Down-Arrow Keys

This will display the Set Point High Limit prompt.

2. Press the Mode Key to view the other parameter

3. Press the Up-Arrow or Down-Arrow Key once to view

4. Press the Up-Arrow or Down-Arrow Key to increase

5. Press the Mode Key to again display the prompt and

6. Press the Mode Key at the Display Build Number

for five seconds.

prompts.

a parameter’s value.

or decrease that value.

again to display the next prompt.

prompt to return to the process value display.

Display Parameter Name & Description Range Default

Process Value Controller

Numeric

Numeric

No Dis­play

No Dis­play

No Dis­play

No Dis­play

No Dis­play

No Dis­play

[SLA]

[SLA]

[Cnt]

[Cnt]

Note:

All values above 999 will be rounded off to fit in the three-character display. Full values can be

read with other interfaces.

Note:

The EHG CL does not support Modbus function code 16 (0x10) Write Multiple Registers. Pa­rameter values must be written individually with function code 6 (0x06) Write Single Registers.

View the present Process Value.

Closed Loop Set Point

Set the set point that the controller
will automatically control to.

Heat Output Power

Read (via Modbus communications)
the present heat output power level.

Alert Status

Read (via Modbus communications)
the present alert status.

Process Comparison Value

Set or read (via Modbus communica­tions) the Process Comparison Value.

Limit Status

Read (via Modbus communications)
the present condition of the limit.

Controller Sensor Status

Read (via Modbus communications)
the present status of the controller
sensor.

Limit Sensor Value

View the present value of the limit
sensor.

Limit High Set Point

Set the high process value that will
trigger the limit.

Control Mode Select

Select a control method.

-18 to 537°C (0 to 999°F) 20°C (68°F)

0°C (32°F) to SLA setting 150°C (302°F)

0 to 100% 0

Alert Low (7)
Alert High (8)
Alert None (6)

5 to 50°C (9 to 90°F) 20°C (68°F)

Bit 5 (0x0020)
0 = Not tripped (process value below

limit high set point)

1 = Tripped (process value exceeds

limit high set point)

Bit 2 (0x0004)
0 = Good
1 = Failure

-18 to 537°C (0 to 999°F) 20°C (68°F)

0 to 438°C (32 to 820°F) 200°C (392°F)

[onF]

On-Off (2)

[PId]

PID (3)

Alert None

0

0

on-off

Modbus
Relative
Address

20

34

22

31

68

63

23

60

33

42

Data Type

& Read/

Write

unsigned
integer

R

unsigned
integer

RWE

unsigned
integer

R

unsigned
integer

R

unsigned
integer

RWE

unsigned
integer

R

unsigned
integer

R

unsigned
integer

R

unsigned
integer

RWE

unsigned
integer

RWE

R: Read
W: Write
E: EEPROM

Watlow Controls 2 EHG CL User’s Guide

Display Parameter Name & Description Range Default

[HyS]

[HyS]

[`Pb]

[ Pb]

[Int]

[Int]

[dEu]

[dEv]

[`Ct]

[ Ct]

[Abt]

[Abt]

[Adr]

[Adr]

[bAU]

[bAU]

[tU`]

[tU ]

[rpp]

[rPP]

[bru]

[brv]

[bPu]

[bPv]

[bbu]

[bbu]

[dru]

[drv]

[dPu]

[dPv]

[dbu]

[dbv]

Note:

All values above 999 will be rounded off to fit in the three-character display. Full values can be

read with other interfaces.

Note:

The EHG CL does not support Modbus function code 16 (0x10) Write Multiple Registers. Pa­rameter values must be written individually with function code 6 (0x06) Write Single Registers.

On-Off Hysteresis

Set the how far below the set point
the temperature can drop before the
heater turns on.

Proportional Band

Set the proportional band in tempera­ture units.

Integral

Set the integral value in minutes per
repeat.

Derivative

Set the derivative value in minutes.

Cycle Time

Set the cycle time in seconds.

Ambient Temperature

View the ambient temperature.

Modbus Device Address

View and or change the present Mod­bus address.

Modbus Baud Rate

Select the communication speed.

Temperature Units

Select the temperature scale.

Restore Programmed Parameters

Restore factory default settings.

Base Release Version

View the controller’s base release
version.

Base Prototype Version

View the controller’s base prototype
version.

Base Build Version

View the controller’s base build num­ber.

Display Release Version

View the interface’s release version.

Display Prototype Version

View the interface’s prototype ver­sion.

Display Build Version

View the interface’s build number.

3 to 28°C (5 to 50°F) 3°C (6°F)

0 to 68°C (0 to 122°F) 0°C or 0°F

0 to 999 0

0 to 999 0

5 to 60 10

0 to 106°C (0 to 190°F) 43°C (77°F)

1 to 247 1

[`96]

9,600 (15)

[192]

19,200 (16)

[384]

38,400 (17)

[``F]

°F (4)

[``C]

°C (5)

[yes] Yes

9,600

°C

No

[`no] No

0 to 9999

- - - - 48

0 to 9999

- - - - 49

0 to 9999

- - - - 50

0 to 9999

- - - - 11

0 to 9999

- - - - 12

0 to 9999

- - - - 13

Modbus
Relative
Address

41

37

38

39

40

24

15

16

17

- - - - - - - -

Data Type

& Read/

unsigned
integer

RWE

signed in­teger

RWE

signed in­teger

RWE

signed in­teger

RWE

unsigned
integer

RWE

unsigned
integer

R

unsigned
integer

RWE

unsigned
integer

RWE

unsigned
integer

RWE

unsigned
integer

R

unsigned
integer

R

unsigned
integer

R

unsigned
integer

R

unsigned
integer

R

unsigned
integer

R

R: Read
W: Write
E: EEPROM

Write

Watlow Controls 3 EHG CL User’s Guide