Pfeiffer Vacuum PPT 200 User manual

OPERATING INSTRUCTIONS
EN
Translation of the Original
PPT 200
Digital Pirani gauge

Dear Customer,
Thank you for choosing a Pfeiffer Vacuum product. Your new gauge is designed to support
you in your individual application with maximum performance and without malfunctions. The
name Pfeiffer Vacuum stands for high-quality vacuum technology, a comprehensive and
complete range of top-quality products and first-class service. From this extensive, practical
experience we have gained a large volume of information that can contribute to efficient
deployment and to your personal safety.
In the knowledge that our product must avoid consuming work output, we trust that our
product can offer you a solution that supports you in the effective and trouble-free
implementation of your individual application.
Please read these operating instructions before putting your product into operation for the
first time. If you have any questions or suggestions, please feel free to contact info@pfeiffer-
vacuum.de.
Further operating instructions from Pfeiffer Vacuum can be found in the Download Center on
our website.
Disclaimer of liability
These operating instructions describe all models and variants of your product. Note that your
product may not be equipped with all features described in this document. Pfeiffer Vacuum
constantly adapts its products to the latest state of the art without prior notice. Please take
into account that online operating instructions can deviate from the printed operating
instructions supplied with your product.
Furthermore, Pfeiffer Vacuum assumes no responsibility or liability for damage resulting from
the use of the product that contradicts its proper use or is explicitly defined as foreseeable
misuse.
Copyright
This document is the intellectual property of Pfeiffer Vacuum and all contents of this
document are protected by copyright. They may not be copied, altered, reproduced or
published without the prior written permission of Pfeiffer Vacuum.
We reserve the right to make changes to the technical data and information in this document.
2/46

Table of contents
1 About this manual 7
1.1 Validity 7
1.1.1 Applicable documents 7
1.1.2 Variants 7
1.2 Target group 7
1.3 Conventions 8
1.3.1 Instructions in the text 8
1.3.2 Pictographs 8
1.3.3 Stickers on product 8
1.3.4 Abbreviations 8
1.4 Trademark proof 9
2 Safety 10
2.1 General safety information 10
2.2 Safety instructions 10
2.3 Safety precautions 12
2.4 Limits of use of the product 13
2.5 Proper use 13
2.6 Foreseeable improper use 13
3 Product description 15
3.1 Function 15
3.2 Identifying the product 15
3.3 Scope of delivery 15
4 Transport and storage 16
4.1 Transporting the product 16
4.2 Storing the product 16
5 Installation 17
5.1 Establish vacuum connection 17
5.2 Creating "RS-485" connection 18
6 Interfaces 20
6.1 Interface RS-485 20
6.2 Pfeiffer Vacuum protocol for RS-485 interface 20
6.2.1 Telegram frame 20
6.2.2 Telegram description 21
6.2.3 Telegram example 1 21
6.2.4 Telegram example 2 21
6.2.5 Data types 22
7 Parameter set 23
7.1 General 23
7.2 Overview of parameters of PPT gauge 23
7.3 Status requests 24
7.4 Pressure values and correction factors 24
8 Operation 25
8.1 Determining effective pressure with correction factors 26
8.2 Reading and setting relay and switch-points 27
9 Disassembly 28
10 Maintenance 29
10.1 Clean the transmitter 29
10.2 Calibrating gauge 31
10.3 Replacing the sensor module 31
Table of contents
3/46

11 Malfunctions 33
12 Shipping 34
13 Recycling and disposal 35
13.1 General disposal information 35
13.2 Dispose of gauges 35
14 Service solutions by Pfeiffer Vacuum 36
15 Spare parts 38
16 Accessories 39
16.1 Accessory information 39
16.2 Ordering accessories 39
17 Technical data and dimensions 40
17.1 General 40
17.2 Technical data 40
17.3 Dimensions 42
UL/CSA certification 43
EC Declaration of Conformity 44
UK Declaration of Conformity 45
Table of contents
4/46

List of tables
Tbl. 1: Applicable documents 7
Tbl. 2: Variants 7
Tbl. 3: Abbreviations used 9
Tbl. 4: Permissible ambient conditions 13
Tbl. 5: Features of the RS-485 interface 20
Tbl. 6: Explanation and meaning of the parameters 23
Tbl. 7: Overview of parameters of PPT gauge 23
Tbl. 8: Parameter set | Status requests 24
Tbl. 9: Parameter set | Pressure values and correction factors 24
Tbl. 10: Operating mode display via "device status" LED 25
Tbl. 11: Correction factor for pressure range < 1 hPa 26
Tbl. 12: Malfunctions 33
Tbl. 13: Spare parts 38
Tbl. 14: Accessories 39
Tbl. 15: Conversion table: Pressure units 40
Tbl. 16: Conversion table: Units for gas throughput 40
Tbl. 17: Measured and pressure values 40
Tbl. 18: Electrical data 40
Tbl. 19: RS-485 interface 41
Tbl. 20: Connection flanges and weight 41
Tbl. 21: Ambient conditions 41
Tbl. 22: Temperatures 41
Tbl. 23: Substances in contact with media 41
List of tables
5/46

List of figures
Fig. 1: Structure of the PPT gauge 15
Fig. 2: Establish vacuum connection 18
Fig. 3: Cross-link via connection RS-485 using connection cables and accessories 19
Fig. 4: Cross-link via RS-485 connection using OmniControl 19
Fig. 5: Connection assignment of RS-485 connecting socket 20
Fig. 6: Examples of reading current pressure values via [P:740] 25
Fig. 7: Gas type dependency of the Pirani sensor 26
Fig. 8: Cleaning measuring chamber 30
Fig. 9: Replace sensor module 32
Fig. 10: Sensor module 38
Fig. 11: PPT 200 with DN 16 ISO-KF 42
Fig. 12: PPT 200 with DN 16 CF-F 42
List of figures
6/46

1 About this manual
IMPORTANT
Read carefully before use.
Keep the manual for future consultation.
1.1 Validity
This document describes the function of the products listed in the following and provides the most im-
portant information for safe use. The description is written in accordance with the valid directives. The
information in this document refers to the current development status of the products. The document
retains its validity assuming that the customer does not make any changes to the product.
1.1.1 Applicable documents
Designation Document
Operating instructions for “Control unit” OmniControl PT 0670
Declaration of conformity A component of these instructions
Tbl. 1: Applicable documents
You can find this document in the Pfeiffer Vacuum Download Center.
1.1.2 Variants
This document applies to products with the following article numbers:
Article number Designation Filament
PT R38 130 PPT 200, DN 16 ISO-KF Tungsten
PT R38 310 PPT 200, DN 16 CF-F Tungsten
Tbl. 2: Variants
You can find the part number on the rating plate of the product.
Pfeiffer Vacuum reserves the right to make technical changes without prior notification.
Information that relates to only one of the products is indicated accordingly.
The figures in this document are not to scale.
The figures show the product with a DN 16 ISO-KF vacuum connection, however, they also apply to the
other vacuum connections where applicable.
Dimensions are provided in mm, unless specified otherwise.
1.2 Target group
These operating instructions are aimed at all persons performing the following activities on the product:
●Transportation
●Setup (Installation)
●Usage and operation
●Decommissioning
●Maintenance and cleaning
●Storage or disposal
The work described in this document is only permitted to be performed by persons with the appropriate
technical qualifications (expert personnel) or who have received the relevant training from Pfeiffer Vac-
uum.
About this manual
7/46

1.3 Conventions
1.3.1 Instructions in the text
Usage instructions in the document follow a general structure that is complete in itself. The required ac-
tion is indicated by an individual step or multi-part action steps.
Individual action step
A horizontal, solid triangle indicates the only step in an action.
►This is an individual action step.
Sequence of multi-part action steps
The numerical list indicates an action with multiple necessary steps.
1. Step 1
2. Step 2
3. ...
1.3.2 Pictographs
The pictographs used in the document indicate useful information.
Note
Tip
Wear laboratory gloves
Perform a visual inspection
1.3.3 Stickers on product
This section describes all the stickers on the product along with their meanings.
D-35614 Asslar
Mod.
P/N
S/N
Input
PPT 200
PT R38 xxx
12345678
24 V DC 2.5 W
Made in Germany 2023/01
Range 1.0x10 - 1000 hPa
-4
Rating plate
The rating plate is located on the back
of the device.
1.3.4 Abbreviations
Abbreviation Explanation
ATM Atmosphere
AR Analog relay
FS Measuring range max. (full scale)
HU Height unit of a 19" rack
HV High vacuum
About this manual
8/46

Abbreviation Explanation
NN Mean sea level
OR Overrange
[P:xxx] Electronic drive unit control parameters. Printed in bold as a three-digit number in
square brackets. Frequently displayed in conjunction with a short description.
Example: [P:312] software version
p Pressure
RS-485 Standard for a physical interface for asynchronous serial data transmission (recom-
mended standard)
TPS Voltage supply (turbo power supply)
UR Underrange
Tbl. 3: Abbreviations used
1.4 Trademark proof
●Binder® is a trademark of Franz Binder GmbH + Co. Elektrische Bauelemente KG.
●Torx® is a trademark of Acument Global Technologies.
About this manual
9/46

2 Safety
2.1 General safety information
The following 4 risk levels and 1 information level are taken into account in this document.
DANGER
Immediately pending danger
Indicates an immediately pending danger that will result in death or serious injury if not observed.
►Instructions to avoid the danger situation
WARNING
Potential pending danger
Indicates a pending danger that could result in death or serious injury if not observed.
►Instructions to avoid the danger situation
CAUTION
Potential pending danger
Indicates a pending danger that could result in minor injuries if not observed.
►Instructions to avoid the danger situation
NOTICE
Danger of damage to property
Is used to highlight actions that are not associated with personal injury.
►Instructions to avoid damage to property
Notes, tips or examples indicate important information about the product or about this docu-
ment.
2.2 Safety instructions
Safety instructions according to product life stages
All safety instructions in this document are based on the results of a risk assessment.
Pfeiffer Vacuum has taken into account all the relevant life stages of the product.
Risks during installation
DANGER
Risk to life due to electric shock
An improperly earthed product is potentially fatal in the event of a fault.
►Connect the product galvanically with the earthed vacuum chamber.
►Ensure that the connection complies with the requirements of a protective bonding according to
EN 61010. (CF and VCR connections comply with this requirement.)
►Use electrically conductive centering rings and circlips for KF connections.
Safety
10/46

DANGER
Danger to life due to dangerous contact voltage
Voltages above 30 V (AC) or 60 V (DC) are considered dangerous in accordance with EN 61010. If
you come into contact with dangerous contact voltage, this can result in injury through electric shocks
or even death.
►Only connect the product to devices which meet the following criteria:
●Requirements of the earthed protective extra-low voltage (PELV)
●Limited power source (LPS) Class 2
►Secure the line to the product.
–Pfeiffer Vacuum measuring and control equipment complies with this requirement.
DANGER
Danger to life from electric shock
When establishing the voltages that exceed the specified safety extra-low voltage (according to IEC
60449 and VDE 0100), the insulating measures will be destroyed. There is a danger to life from elec-
tric shock at the communication interfaces.
►Connect only suitable devices to the bus system.
Risks during operation
DANGER
Danger to life from electric shock caused by moisture ingress
Water that has entered the unit will result in personal injury through electric shocks.
►Only operate the unit in a dry environment.
►Operate the unit away from fluids and sources of moisture.
►Do not switch on the unit if fluid has entered it. Instead contact Pfeiffer Vacuum Service.
►Always disconnect the power supply before cleaning the unit.
WARNING
Risk of injury resulting from overpressure in the vacuum system
Opening tensioning pieces with an overpressure > 1000 hPa in the vacuum system can lead to inju-
ries as a result of flying parts, and escaping process medium could prove harmful to health.
Elastomer seals in KF connections (e.g. O-rings) are not resistant to pressures > 2500 hPa. This
could prove harmful to health due to escaping process medium.
►Do not open any tensioning pieces when overpressure is prevalent in the vacuum system.
►Use suitable tensioning pieces for overpressure.
►Use tensioning pieces which can only be opened and closed using a tool (e.g. tightening strap-
circlip).
►Use sealing rings with an outer centering ring.
Risks during maintenance
DANGER
Danger to life from electric shock caused by moisture ingress
Water that has entered the unit will result in personal injury through electric shocks.
►Only operate the unit in a dry environment.
►Operate the unit away from fluids and sources of moisture.
►Do not switch on the unit if fluid has entered it. Instead contact Pfeiffer Vacuum Service.
►Always disconnect the power supply before cleaning the unit.
Safety
11/46

WARNING
Health hazard through poisoning from toxic contaminated components or devices
Toxic process media result in contamination of devices or parts of them. During maintenance work,
there is a risk to health from contact with these poisonous substances. Illegal disposal of toxic sub-
stances causes environmental damage.
►Take suitable safety precautions and prevent health hazards or environmental pollution by toxic
process media.
►Decontaminate affected parts before carrying out maintenance work.
►Wear protective equipment.
WARNING
Health hazards due to cleaning agent
The cleaning agent being used causes health hazards which could include, for example, poisoning,
allergies, skin irritations, chemical burns or damage to the airways.
►When handling cleaning agents, observe the applicable regulations.
►Adhere to safety measures regarding handling and disposal of cleaning agents.
►Be aware of potential reactions with product materials.
Risks when shipping
WARNING
Risk of poisoning from contaminated products
Where products that contain harmful substances are shipped for maintenance or repair purposes, the
health and safety of service personnel is at risk.
►Comply with the instructions for safe distribution.
Risks during disposal
WARNING
Health hazard through poisoning from toxic contaminated components or devices
Toxic process media result in contamination of devices or parts of them. During maintenance work,
there is a risk to health from contact with these poisonous substances. Illegal disposal of toxic sub-
stances causes environmental damage.
►Take suitable safety precautions and prevent health hazards or environmental pollution by toxic
process media.
►Decontaminate affected parts before carrying out maintenance work.
►Wear protective equipment.
2.3 Safety precautions
The product is designed according to the latest technology and recognized safety engineering rules.
Nevertheless, improper use can result in danger to operator all third party life and limb, and product
damage and additional property damage.
Duty to provide information on potential dangers
The product holder or user is obliged to make all operating personnel aware of dangers
posed by this product.
Every person who is involved in the installation, operation or maintenance of the product
must read, understand and adhere to the safety-related parts of this document.
Safety
12/46

Infringement of conformity due to modifications to the product
The Declaration of Conformity from the manufacturer is no longer valid if the operator
changes the original product or installs additional equipment.
●Following the installation into a system, the operator is required to check and re-evalu-
ate the conformity of the overall system in the context of the relevant European Direc-
tives, before commissioning that system.
General safety precautions when handling the product
►Observe all applicable safety and accident prevention regulations.
►Check that all safety measures are observed at regular intervals.
►Pass on safety instructions to all other users.
►Do not expose body parts to the vacuum.
►Always ensure a secure connection to the earthed conductor (PE).
►Never disconnect plug connections during operation.
►Observe the above shutdown procedures.
►Keep lines and cables away from hot surfaces (> 70 °C).
►Do not carry out your own conversions or modifications on the device.
►Observe the unit protection degree prior to installation or operation in other environments.
►Provide suitable touch protection, if the surface temperature exceeds 70 °C.
►Inform yourself about any contamination before starting work.
2.4 Limits of use of the product
Parameter Value
Air pressure 800 to 1060 hPa
Relative humidity of air At temperatures up to +30°C max. 80%
At temperatures up to +40°C max. 50%
non-condensing
Mounting orientation Arbitrary
Usage Only in indoor areas
Installation altitude max. 2000 m NN
Protection degree IP54
Tbl. 4: Permissible ambient conditions
2.5 Proper use
The PPT 200 gauge is used for vacuum measurement of air, gases and gauges outside their explosion
limits, within the range of 1 × 10-4 to 1000 hPa.
Use the product according to its intended purpose
►Operate the gauge with a Pfeiffer Vacuum total pressure measuring and control unit or with an
evaluation unit provided by the customer.
►Install, operate and maintain the gauge exclusively as prescribed in these operating instructions.
►Observe the limits of use according to the technical data.
►Observe the technical data.
2.6 Foreseeable improper use
Improper use of the product invalidates all warranty and liability claims. Any use that is counter to the
purpose of the product, whether intentional or unintentional, is regarded as improper use; in particular:
Use of the product in a way not specified by Pfeiffer Vacuum affects the protection provided by the
product.
●Use outside the mechanical and electrical limits of use
●Use with corrosive or explosive media, if this is not explicitly permitted
●Use for the measurement of highly flammable or combustible gases mixed with an oxidizing agent
(e.g. atmospheric oxygen) within the explosion limits
Safety
13/46

●Use outdoors
●Use after technical changes (inside or outside on the product)
●Use with replacement or accessory parts that are not suitable or not approved
Safety
14/46

3 Product description
3.1 Function
The digital gauge has a Pirani measurement system.
The gauge responds to measured value requests, type requests and adjustment commands.
device status
RS485
RS485
adr
9
11
15
5
13
3
7
1
1
2
3
Fig. 1: Structure of the PPT gauge
1 RS-485 address selector switch 3 "RS-485" connector
2 Status LED for the gauge
3.2 Identifying the product
You will need all the data from the rating plate to safely identify the product when communicating with
Pfeiffer Vacuum.
►To ensure clear identification of the product when communicating with Pfeiffer Vacuum, always
keep all of the information on the rating plate to hand.
3.3 Scope of delivery
●Gauge
●Operating instructions
Unpacking the product and checking completeness of the shipment
1. Unpack the product.
2. Remove the transport fasteners, transport protection etc.
3. Store the transport fasteners, transport protection etc. in a safe place.
4. Check that the shipment is complete.
5. Ensure that no parts are damaged.
Product description
15/46

4 Transport and storage
4.1 Transporting the product
NOTICE
Damage caused by incorrect transport
Transport in unsuitable packaging or failure to install all transport locks can result in damage to the
product.
►Comply with the instructions for safe transport.
Packing
We recommend keeping the transport packaging and original protective cover.
Transport product safely
►Observe the weight specified on the transport packaging.
►Where possible, always transport or ship the product in the original transport packaging.
►Always use dense and impact-proof transport packaging for the product.
►Remove the existing protective cover and transport protections only immediately prior to installa-
tion.
►Reattach transport locks and transport protections prior to each transport.
4.2 Storing the product
NOTICE
Damage caused by improper storage
Improper storage will lead to damage to the product.
Static charging, moisture, etc. will lead to defects on the electronic components.
►Comply with the instructions for safe storage.
Packing
We recommend storing the product in its original packaging.
Store product safely
►Store the product in a cool, dry, dust-free place, where it is protected against impacts and me-
chanical vibration.
►Always use dense and impact-proof packaging for the product.
►Where possible, store the product in its original packaging.
►Store electronic components in antistatic packaging.
►Maintain the permissible storage temperature.
►Avoid extreme fluctuations of the ambient temperature.
►Avoid high air humidity.
►Seal connections with the original protective caps.
►Protect the product with the original transport protection (where available).
Transport and storage
16/46

5 Installation
5.1 Establish vacuum connection
DANGER
Risk to life due to electric shock
An improperly earthed product is potentially fatal in the event of a fault.
►Connect the product galvanically with the earthed vacuum chamber.
►Ensure that the connection complies with the requirements of a protective bonding according to
EN 61010. (CF and VCR connections comply with this requirement.)
►Use electrically conductive centering rings and circlips for KF connections.
WARNING
Risk of injury resulting from overpressure in the vacuum system
Opening tensioning pieces with an overpressure > 1000 hPa in the vacuum system can lead to inju-
ries as a result of flying parts, and escaping process medium could prove harmful to health.
Elastomer seals in KF connections (e.g. O-rings) are not resistant to pressures > 2500 hPa. This
could prove harmful to health due to escaping process medium.
►Do not open any tensioning pieces when overpressure is prevalent in the vacuum system.
►Use suitable tensioning pieces for overpressure.
►Use tensioning pieces which can only be opened and closed using a tool (e.g. tightening strap-
circlip).
►Use sealing rings with an outer centering ring.
NOTICE
Impairment from contamination and damage
Touching the devices or components with bare hands increases the desorption rate and leads to in-
correct measurements. Dirt (e.g. dust, fingerprints, etc.) and damage impair the function.
►When working on high or ultra high vacuum systems, always wear clean, lint-free and powder-
free laboratory gloves.
►Only use clean tools.
►Make sure that the connection flanges are free of grease.
►Remove protective caps and protective covers from flanges and connections only when necessa-
ry.
►Carry out all work in a well lit area.
Prerequisites
●Appropriate ambient conditions
●Operating temperature within permissible range
●Adequate room available for electrical connection (e.g. permissible bending radii for cables)
Installation
17/46

5
1
4
3
2
Fig. 2: Establish vacuum connection
1 Seal with centering ring 4 Seal with centering ring and filter
2 Gauge 5 Tensioning piece
3 Protective cap
Recommendations
►Ensure where possible that the gauge is not exposed to any vibrations during operation, as vibra-
tions in general will lead to deviations in the measured values.
►Mount the gauge in a horizontal to upright mounting orientation (flange facing downwards).
–This prevents condensate and particles from accumulating in the measurement chamber.
►Fit a seal with centering ring and filter for applications susceptible to pollution and to protect the
measuring system against contamination.
Procedure
1. Remove the protective cap and store in a safe place.
2. Assemble the gauge with vacuum components from the Pfeiffer Vacuum Components Shop on
the vacuum system.
5.2 Creating "RS-485" connection
DANGER
Danger to life due to dangerous contact voltage
Voltages above 30 V (AC) or 60 V (DC) are considered dangerous in accordance with EN 61010. If
you come into contact with dangerous contact voltage, this can result in injury through electric shocks
or even death.
►Only connect the product to devices which meet the following criteria:
●Requirements of the earthed protective extra-low voltage (PELV)
●Limited power source (LPS) Class 2
►Secure the line to the product.
–Pfeiffer Vacuum measuring and control equipment complies with this requirement.
NOTICE
Property damage due to ground contact of electronics
Disconnecting or connecting the "RS-485" plug-and-socket connection with the voltage supply
switched leads to the destruction of electronic components.
►Always interrupt the voltage supply before you plug in or unplug the “RS-485” power supply plug.
►Switch off the power supply pack.
►After switching off the power supply pack, wait until the residual load has dispersed completely
before disconnecting or connecting the plug-and-socket connection.
Installation
18/46

The interface designated "RS-485" is used to connect an external power supply pack (TPS), a control
unit or a PC.
Required tools
●Slot screwdriver
1 2
1 2
22
1
34 5
Fig. 3: Cross-link via connection RS-485 using connection cables and accessories
1 Supply cable for power supply pack 4 USB/RS-485 converter
2 Y-connector for RS-485 5 PC
3 Interface cable M12
1 2
1 2
1
2
1
3
Fig. 4: Cross-link via RS-485 connection using OmniControl
1 Y-connector for RS-485 3 OmniControl control unit
2 Interface cable M12
Set RS-485 address
1. Remove the rubber plug from the RS-485 address selector switch.
2. Set the RS-485 address with the RS-485 address selector switch on the gauge.
3. Place the rubber plug back on the RS-485 address selector switch.
Ensure protection degree of the gauge
►After setting the RS-485 address, place the rubber plug back on the RS-485 address selector
switch to establish the specified protection degree.
Cross-linked via the RS-485 connection
1. Install the devices according to the specification for RS-485 interfaces.
2. Make sure that all devices connected to the bus have different RS-485 device addresses.
3. Connect all devices with RS-485 D+ and RS-485 D- to the bus.
Connect Pfeiffer Vacuum display and control units or a PC
►Use a connecting cable from the DigiLine accessories range.
►Connect only one external control unit to the RS-485 interface at a time.
►If needed, connect a PC via the USB/RS-485 converter.
Installation
19/46

6 Interfaces
6.1 Interface RS-485
DANGER
Danger to life from electric shock
When establishing the voltages that exceed the specified safety extra-low voltage (according to IEC
60449 and VDE 0100), the insulating measures will be destroyed. There is a danger to life from elec-
tric shock at the communication interfaces.
►Connect only suitable devices to the bus system.
The gauge communicates via the "RS-485" interface. The gauge has the addresses 1 through 16.
Designation Value
Serial interface RS-485
Baud rate 9600 Baud
Data word length 8 bit
Parity none (no parity)
Stop bits 1
Tbl. 5: Features of the RS-485 interface
1 2
34
5
Fig. 5: Connection assignment of RS-485 connecting socket
1 RS-485 D+ 4 RS-485 D-
2 +24 V DC 5 not connected
3 GND
6.2 Pfeiffer Vacuum protocol for RS-485 interface
6.2.1 Telegram frame
The telegram frame of the Pfeiffer Vacuum protocol contains only ASCII code characters [32; 127], the
exception being the end character of the telegram CR. Basically, a host (e.g. a PC) sends a tele-
gram, which a device (e.g. electronic drive unit or gauge) responds to.
a2 a1 a0 * 0 n2 n1 n0 l1 l0 dn ... d0 c2 c1 c0 CR
a2 – a0 Unit address for device
● Individual address of the unit ["001";"016"]
* Action according to telegram description
n2 – n0 Pfeiffer Vacuum parameter numbers
I1 – I0 Data length dn to d0
dn – d0 Data in the respective data type (see chapter “Data types”, page 22).
c2 – c0 Checksum (sum of ASCII values of cells a2 to d0) modulo 256
CRcarriage return (ASCII 13)
Interfaces
20/46