Condair Modbus RTU User manual

Modbus
Installation and
Operation Manual
Using Modbus with Condair
Humidifiers. Includes installation,
operation maintenance and
troubleshooting information.
2560599-F | 15 June 2018
Important: Read and save these instructions. This guide to be left with equipment owner.

Thank you for choosing Condair.
Proprietary Notice
This document and the information disclosed herein are proprietary data of Condair Group AG. Neither this
document nor the information contained herein shall be reproduced, used, or disclosed to others without the
written authorization of Condair Group AG., except to the extent required for installation or maintenance of
recipient’s equipment.
Liability Notice
Condair Group AG does not accept any liability for installations of humidity equipment installed by unqualified
personnel or the use of parts/components/equipment that are not authorized or approved by Condair Group
AG.
Copyright Notice
Copyright 2018, Condair Group AG. All rights reserved.
INSTALLATION DATE (MM/DD/YYYY)
MODEL #
SERIAL #
CYLINDER #

Contents
Introduction 2
Requirements 2
Wiring Connections 2
EL/NH-EL Models 4
NHTC, GSTC, SETC, and MHTC Models 5
MES2 and RH2 Models 5
NHRS Models 5
Addressing and Communications 10
EL Electrode Steam Humidifiers 10
NH-EL Electrode Steam Humidifiers 16
NHTC Electrode Steam Humidifiers 21
GSTC Gas Fired Steam Humidifiers 27
SETC Steam Exchange Humidifiers 31
MHTC Evaporative Media Humidifiers 35
MES2 and RH2 Models 39
NHRS Electric Steam Humidifiers 46
Troubleshooting 49
Appendix A 52
Modbus –Field Retrofit for NHRS Models 52

1 | Modbus Installation
CAUTION: Servicing
Disconnect main power before any servicing.
The plumbing and electrical compartments contain high voltage components and
wiring. Access should be limited to authorized personnel only.
During and following operation of the humidifier, the steam and components in
contact with the steam such as the blower pack, steam lines, steam distributors,
and condensate lines can become hot and can burn if touched.
Condair Group AG does not accept any liability for installations of humidity
equipment installed by unqualified personnel or the use of
parts/components/equipment that are not authorized or approved by Condair
Group AG.
CAUTION: Electrical
All electrical work should be done according to local and national electrical code.
Electrical connection to be performed by a licensed electrician.
CAUTION: Installation
Do not mount on hot surfaces.
Do not mount in area where freezing can occur.
Do not mount on vibrating surface.
Do not mount on floor.
Regardless of selecting on/off or modulating control method, Condair humidifiers
must have a closed circuit across its on/off security loop control terminal to
operate. Condair highly recommends the use of a duct high limit humidistat.

Modbus Installation | 2
Introduction
Many Condair humidifiers feature control boards that include Modbus RTU and can connect to
Modbus networks right out of the box. This document describes how to connect these
humidifiers to such a network and defines the parameters that may be monitored.
Please note that there are differences between Modbus RTU and Modbus TCP. Condair
humidifiers are Modbus RTU capable and require a gateway (by others) for Modbus TCP
networks. Contact the factory for more information on Modbus TCP communications.
Requirements
EL/NH-EL Humidifiers are capable of Modbus RTU and require no additional hardware for this
connection.
Condair humidifiers that feature that Total Controller (“TC”) control boards are also capable of
Modbus RTU. These include the NHTC, the GSTC, SETC, and MHTC humidifiers.
Additionally, the RH2 and MES-2 models feature a digital control board that supports Modbus,
however these models require an adapter board to provide the Modbus interface. Finally, the
NHRS also supports Modbus communications; however a TTL converter is required for this
functionality. Refer to following table for more information, items described as “optional” are
for convenience (but not required for Modbus), while items listed as required are needed for
Modbus functionality:
Table 1: Modbus Accessories
Part
Number
Kit Name
Kit Description
2553787
NHTC, GSTC, SETC Modbus Connection
Optional adapter cable for NHTC, GSTC, SETC.
2560630
MHTC Modbus Interface
Optional terminal block for MHTC Modbus interface.
2531585
Modbus Option for OEM Digital Board
Required adapter board and terminals for Modbus
connections.
2560631
NHRS Modbus converter
Required TTL converter for NHRS Modbus
connections.
Please consult your local Condair representative to orders connection kits.
Wiring Connections
Using the correct wiring between the humidifier and the Modbus network is important to ensure
reliable communications and reduce the impact of electrical interference. The recommended
wire type is 18 -24 AWG, shielded twisted pair wire with 120 Ohm characteristic impedance. As
an alternative, CAT-5 (“Ethernet”) cable exceeds these specifications and may be used. In this
case, only two of the conductors and the wire shield will be used; care must be taken to isolate
any unused conductors.
Regardless of which wire type is used ensuring the correct shield terminations is necessary to
prevent electrical interference. The wire shield should be terminated at either the humidifier or
the Modbus system, but not both. This allows induced current to “drain”; if the shield is
terminated at both ends it will function as a conductor and can actually increase electrical
interference. To minimize signal loss a wire run should not exceed 2000 feet. Additionally, to
ensure communication reliability, it is recommended that no more than 8 humidifiers are

3 | Modbus Installation
connected to a single chain/bus. The humidifiers should be the same type but do not need to
be the same capacity. For example it is not recommended to have an NHTC and a GSTC as part
of the same chain, but it is acceptable to have an NHTC-200 and an NHTC-30 as part of the
same chain. Connecting additional non-Condair equipment into a Modbus chain is possible;
however it is important to ensure that all devices are operating with identical baud rate, parity,
and stop bits, and that each device has a unique Modbus address.
Figure 1: Example Daisy Chain Diagram for EL/NH-EL, NHTC, GS, SE

Modbus Installation | 4
EL/NH-EL Models
The EL/NH-EL models use a 3-pole connector on the main processor card for Modbus
connection. This 3-pole connector is provided with all EL/NH-EL and connections can be made
directly to this plug. Refer to Figure 2 and Figure 3 for connection location and wiring.
Please note: there is a 120 Ohm termination resistor available on board. When the jumper J4
is on, 120 Ohm is enabled. When the jumper J4 is off, 120 Ohm is disabled.
Figure 2: EL/NH-EL Modbus 3-Pole Plug Location

5 | Modbus Installation
NHTC, GSTC, SETC, and MHTC Models
The NHTC, GSTC, SETC, and MHTC models use a multifunction RJ45 plug on the mainboard to
provide Modbus communications. Connections can be made directly to this plug or,
alternatively, using one of accessories listed above.
Refer to figure 4 for information on the wiring connections for these units.
Note: This instruction manual covers the connections and points for the GSTC B+ and SETC B+
models only. Older models, manufactured pre-2009 do not include the RJ45 plug and require
an additional interface cable. Contact Condair for information on connecting these units.
MES2 and RH2 Models
The MES2 and RH2 models require a Modbus support board to provide a connection point. This
board can be factory installed if indicated at time of order, or retrofit to existing units in the field.
Refer to Figure 5 for information on the wiring connections for these units.
NHRS Models
The NHRS models require a Modbus kit to translate information from the processor board into
Modbus RTU information. This kit can be factory installed if specified at time of order or retrofit
to existing units in the field. Refer to figure 6 for information on the wiring connections for these
units.

Modbus Installation | 6
Figure 3: EL/NH-EL Modbus Wiring Diagram

7 | Modbus Installation
Figure 4: TC Modbus Wiring Diagram

Modbus Installation | 8
Figure 5: MES2 and RH2 Modbus Wiring Diagram

9 | Modbus Installation
Figure 6: NHRS Modbus Wiring Diagram

Modbus Installation | 10
Addressing and Communications
Once the humidifier has been wired to the network, control variables must be mapped to allow
for control of the humidifier. The specific variables and communications requirements for each
humidifier are described in the following sections.
EL Electrode Steam Humidifiers
After wiring connections have been completed, the humidifier needs to be setup to operate and
communicate either through the Modbus or BACnet interface.
Modbus Communication Set-up
The default Modbus address for the EL is 10. If multiple units were included on an order, the
addresses of individual units may vary. To view or change the Modbus address:
1Press the Menu icon on the lower left corner of the screen, to access the menu.
2When prompted for a password, enter 0335 using the number pad. Press the Check Mark
icon to confirm.
3Select the Configuration menu.
4Select the Comms. menu.
5Using the navigation buttons on the top right of the screen, scroll down to the Modbus
Parameters.
Note: By default, Modbus is disabled. To enable Modbus, select Modbus under Modbus
Parameters. Select ON and confirm the selection by pressing the Check Mark button.
6Select the Modbus Address setting. Using the Up and Down arrows, select a value between
1 and 247 inclusive as desired and press the Check Mark button to confirm the selection. It
is recommended to leave the parity and baud rate settings to their factory defaults (Even
and 9600 respectively) unless communication problems occur.
7Press Back repeatedly until you return to the home screen.
This procedure is summarized below:
Main Menu > 0335 > Configuration > Comms. Menu > Modbus Parameters >
Addr: 10 (1 –247 acceptable)
Parity: Even (None, Even, Odd)
Baud Rate: 9600 (9600, 19200, 38400, 115200)

11 | Modbus Installation
Control Signal Setting
By default the humidifier is configured operate on a hardwired control signal supplied through
the unit terminal strip. This can be changed to allow the humidifier to function entirely through
its Modbus or BACnet interface.
To adjust this setting:
1Press the Menu icon on the lower left corner of the screen, to access the menu.
2When prompted for a password, enter 0335 using the number pad. Press the Check Mark
icon to confirm.
3Select the Configuration menu.
4Select the Control Settings menu. The following settings can be adjusted:
Source
Analog: Use hardwired control signal
Modbus: Write control signal through Modbus interface
Control Mode
Demand: Use a demand control signal
RH P: Use a sensor value and proportional
RH PI: Use a sensor value and proportional-integral control band
Control Channels
Single: Use a signal channel control signal
Dual: Use a dual channel control signal
Note: Refer to the Operator Interface section of the EL Operation and Maintenance Manual for
more information on the above settings.
5Press Check Mark to confirm choice and then Back repeatedly to return to the home screen
when complete.
This procedure is summarized below:
Main Menu > 0335 > Configuration > Control Settings >
Source: Analog, Modbus,
Control Mode: Demand, RH P, or RH PI
Control Channels: Single or Dual
Modbus Parameters
The EL uses the following parameters for Modbus communication:
Signaling Type
EIA-485
Transmission Mode
RTU
Baud Rate
9600
Data Bits
8
Stop Bits
1
Parity
Even
Address / Unit Number
10*
*Default, may vary for multi-unit orders.
It is important to note that the signaling type, transmission mode, data bits and stop bits cannot
be modified. Parity, baud rate and unit address can be modified as required.

Modbus Installation | 12
The following points may be mapped for control:
Table 2: EL Humidifier Modbus Parameters
Parameter
Name
Description
Modbus
Addr.
Type
Format
Range
Unit
W/R
Details
Remote
Disable
Remotely disable
steam production
for the unit
40001
Holding
Register
Integer
0 OR 1
-
WRITE/READ
0 = Idle/Humidify
1 = Disable
Manual
Capacity A
Sets a manual
capacity limit
restriction for
cylinder A
40002
Holding
Register
Integer
20-100
%
WRITE/READ
Limits output to
percentage of total
cylinder capacity for
cylinder A (EL-150
and EL-200 models
only)
Setpoint
Channel A1
Sets the desired
humidity setpoint
value for Channel
A1
40003
Holding
Register
Integer
0-95
%
WRITE/READ
Use only when
sending RH values to
Digital RH/Demand
A1.
For most common
configurations this is
the primary space
setpoint
Setpoint
Channel A2
Sets the humidity
high limit setpoint
value for Channel
A2
40004
Holding
Register
Integer
10-95
%
WRITE/READ
Use only when
sending RH value to
Digital RH/Demand
A2 with dual channel
control enabled
Digital
RH/Demand
A1
Actual humidity
or demand via
BACnet unit A
40005
Holding
Register
Integer
0-100
%
WRITE/READ
Requires Modbus or
BACnet to be
enabled. For most
common
configurations, this is
the primary control
signal
Digital
RH/Demand
A2
Actual humidity
or limiter via
BACnet unit A
40006
Holding
Register
Integer
0-100
%
WRITE/READ
Requires Modbus or
BACnet to be
enabled. Only applies
to EL-150 and EL-200
with cylinders in
independent
operation mode
Manual
Capacity B
Sets a manual
capacity limit
restriction for
cylinder B
40007
Holding
Register
Integer
20-100
%
WRITE/READ
Limits output to
percentage of total
cylinder capacity for
cylinder B (EL-150
and EL-200 models
only)
Setpoint
Channel B1
Sets the desired
humidity setpoint
value for Channel
B1
40008
Holding
Register
Integer
0-95%
%
WRITE/READ
Use only with EL-150
and EL-200 models
when sending RH
value to Digital
RH/Demand B1 and
cylinders are in
independent
operation mode

13 | Modbus Installation
Parameter
Name
Description
Modbus
Addr.
Type
Format
Range
Unit
W/R
Details
Setpoint
Channel B2
Sets the humidity
high limit setpoint
value for Channel
B2
40009
Holding
Register
Integer
10-95
%
WRITE/READ
Use only with EL-150
and EL-200 models
when sending RH
value to Digital
RH/Demand B2 with
dual channel control
enabled and
cylinders are in
independent
operation mode
Digital
RH/Demand
B1
Actual humidity
or demand via
BACnet unit B
40010
Holding
Register
Integer
0-100
%
WRITE/READ
Requires Modbus or
BACnet to be
enabled.
Only applies to EL-
150 and EL-200 with
dual channel control
enabled
Digital
RH/Demand
B2
Actual humidity
or limiter via
BACnet unit B
40011
Holding
Register
Integer
0-100
%
WRITE/READ
Requires Modbus or
BACnet to be
enabled.
Only applies to EL-
150 and EL-200 with
cylinders dual
channel control
enabled and
cylinders in
independent
operation mode
BAND
CHANNEL A1
P-band unit A
(proportional
band)
40017
Holding
Register
Integer
6-65
%
WRITE/READ
BAND
CHANNEL A2
P-band unit A
(proportional
band) limiter
40018
Holding
Register
Integer
6-65
%
WRITE/READ
BAND
CHANNEL B1
P-band unit B
(proportional
band)
40019
Holding
Register
Integer
6-65
%
WRITE/READ
BAND
CHANNEL B2
P-band unit B
(proportional
band) limiter
40020
Holding
Register
Integer
6-65
%
WRITE/READ
ITime Channel
A1
Integral time
channel 1 unit A
40021
Holding
Register
Integer
1-60
min
WRITE/READ
Damp
Channel A2
Damp time
channel 2 unit A
40022
Holding
Register
Integer
1-60
sec
WRITE/READ
ITime Channel
B1
Integral time
channel 1 unit B
40023
Holding
Register
Integer
1-60
min
WRITE/READ
Damp
Channel B2
Damp time
channel 2 unit B
40024
Holding
Register
Integer
1-60
sec
WRITE/READ
Enable Input
A
Enable contact
unit A
30002
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On
Channel A1
Input signal
channel 1 unit A
30004
Input
Register
Integer
0-100
%
READ
Displays channel 1
demand/sensed RH
as a percentage of
cylinder capacity for
cylinder A
Channel A2
Limiter signal
channel 2 unit A
30005
Input
Register
Integer
0-100
%
READ
Displays channel 2
demand/sensed RH
as a percentage of
cylinder capacity for
cylinder A

Modbus Installation | 14
Parameter
Name
Description
Modbus
Addr.
Type
Format
Range
Unit
W/R
Details
System
Demand A
System Demand A
30006
Input
Register
Integer
0-100
%
READ
Demand Mode:
Summation of
Channel A1 and
Channel A2
RH Mode:
PID calculation
Safety Loop A
External safety
loop unit A
30007
Input
Register
Integer
0 OR 1
-
READ
0 = Open
1 = Closed
Blower Pack A
Blower ready unit
A
30008
Input
Register
Integer
0 OR 1
-
READ
0 = Open
1 = Closed
FanActivate A
External fan unit
A
30009
Input
Register
Integer
0 OR 1
-
READ
0 = Open
1 = Closed
Operating
Hours A
Operating hours
unit A
30010
Input
Register
Float CD
AB
0-5000
Hrs
FLOAT CD AB
Displays the total
time cylinder A has
been running since
last reset
Enable Input
B
Enable contact
unit B
30012
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On
Channel B1
Input signal
channel 1 unit B
30014
Input
Register
Integer
0-100
%
READ
Displays channel 1
demand/sensed RH
as a percentage of
cylinder capacity for
cylinder B (EL-150
and EL-200 models
only)
Channel B2
Limiter signal
channel 2 unit B
30015
Input
Register
Integer
0-100
%
READ
Displays channel 2
demand/sensed RH
as a percentage of
cylinder capacity for
cylinder B (EL-150
and EL-200 models
only)
System
Demand B
System Demand B
30016
Input
Register
Integer
0-100
%
READ
Demand Mode:
Summation of
Channel B1 and
Channel B2
RH Mode:
PID calculation
Safety Loop B
External safety
loop unit B
30017
Input
Register
Integer
0 OR 1
-
READ
0 = Open
1 = Closed
Blower Pack B
Blower ready unit
B
30018
Input
Register
Integer
0 OR 1
-
READ
0 = Open
1 = Closed
FanActivate B
External fan unit
B
30019
Input
Register
Integer
0 OR 1
-
READ
0 = Open
1 = Closed
Operating
Hours B
Operating hours
unit B
30020
Input
Register
Float CD
AB
0-5000
Hrs
FLOAT CD AB
Displays the total
time cylinder B has
been running since
last reset

15 | Modbus Installation
Parameter
Name
Description
Modbus
Addr.
Type
Format
Range
Unit
W/R
Details
Status A
Operating status
unit A
31003
Input
Register
Integer
0-13
-
READ
0-Humidifying
1-Standby
2-Idle Drained
3-Keep Warm
4-Filling
5-Draining
6-Remote Off
7-Safety Loop
8-Warning
9-Fault
10-Blower Pack
11-Stopped
12-Partial Drained
13-Self Test
Service Status
B
Maintenance and
malfunctions
status unit B
31026
Input
Register
Integer
0-13
-
READ
0-Humidifying
1-Standby
2-Idle Drained
3-Keep Warm
4-Filling
5-Draining
6-Remote Off
7-Safety Loop
8-Warning
9-Fault
10-Blower Pack
11-Stopped
12-Partial Drained
13-Self Test
Main
Contactor A
Contactor unit A
31200
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On
Main
Contactor B
Contactor unit B
31201
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On
Inlet A
Inlet valve unit A
31202
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On
Inlet B
Inlet valve unit B
31203
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On
Drain A
Drain valve unit A
31204
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On
Drain B
Drain valve unit B
31205
Input
Register
Integer
0 OR 1
-
READ
0 = Off
1 = On

Modbus Installation | 16
NH-EL Electrode Steam Humidifiers
After wiring connections have been completed, the humidifier needs to be setup to operate and
communicate either through the Modbus or BACnet interface.
Modbus Communication Set-up
The default Modbus address for an NH-EL is 10. If multiple units were included on an order, the
addresses of individual units may vary. To view or change the Modbus address:
8Press the Menu icon on the lower left corner of the screen, to access the menu.
9When prompted for a password, enter 0335 using the number pad. Press the Check Mark
icon to confirm.
10 Select the Configuration menu.
11 Select the Comms. menu.
12 Using the navigation buttons on the top right of the screen, scroll down to the Modbus
Parameters.
Note: By default, Modbus is disabled. To enable Modbus, select Modbus under Modbus
Parameters. Select ON and confirm the selection by pressing the Check Mark button.
13 Select the Modbus Address setting. Using the Up and Down arrows, select a value between
1 and 247 inclusive as desired and press the Check Mark button to confirm the selection. It
is recommended to leave the parity and baud rate settings to their factory defaults (Even
and 9600 respectively) unless communication problems occur.
14 Press Back repeatedly until you return to the home screen.
This procedure is summarized below:
Main Menu > 0335 > Configuration > Comms. Menu > Modbus Parameters >
Addr: 10 (1 –247 acceptable)
Parity: Even (None, Even, Odd)
Baud Rate: 9600 (9600, 19200, 38400, 115200)

17 | Modbus Installation
Control Signal Setting
By default the humidifier is configured operate on a hardwired control signal supplied through
the unit terminal strip. This can be changed to allow the humidifier to function entirely through
its Modbus or BACnet interface.
To adjust this setting:
6Press the Menu icon on the lower left corner of the screen, to access the menu.
7When prompted for a password, enter 0335 using the number pad. Press the Check Mark
icon to confirm.
8Select the Configuration menu.
9Select the Control Settings menu. The following settings can be adjusted:
Source
Analog: Use hardwired control signal
Modbus: Write control signal through Modbus interface
Control Mode
Demand: Use a demand control signal
RH P: Use a sensor value and proportional
RH PI: Use a sensor value and proportional-integral control band
Control Channels
Single: Use a signal channel control signal
Dual: Use a dual channel control signal
Note: Refer to the CONTROL SETTING section of the NH Series Installation and Operation
Manual for more information on the above settings.
10 Press Check Mark to confirm choice and then Back repeatedly to return to the home screen
when complete.
This procedure is summarized below:
Main Menu > 0335 > Configuration > Control Settings >
Source: Analog, Modbus,
Control Mode: Demand, RH P, or RH PI
Control Channels: Single or Dual
Modbus Parameters
The NH-EL uses the following parameters for Modbus communication:
Signaling Type
EIA-485
Transmission Mode
RTU
Baud Rate
9600
Data Bits
8
Stop Bits
1
Parity
Even
Address / Unit Number
10*
*Default, may vary for multi-unit orders.
It is important to note that the signaling type, transmission mode, data bits and stop bits cannot
be modified. Parity, baud rate and unit address can be modified as required.