ZBXYO Series Evaluation interface board for XYO optical oxygen sensors FEATURES · Provides three outputs simultaneously: - RS232 (serial interface voltage levels) - RS485 (Modbus RTU) allows multiple sensors to be addressed on a bus - 0...5 V analog output for basic measurements of oxygen only · Auto detects ppO2 or O2% variants of XYO sensor · RoHS compliant SPECIFICATIONS Maximum ratings Supply voltage 4.75...5.25 VDC Supply current <50 mA Temperature limits Storage Operating 0...60 °C 0...50 °C ELECTRICAL CONNECTION Notes: Care should be taken not to connect the 5 V supply voltage and 0 V connections the wrong way round as this may damage the interface. With power supplied correctly the green LED on the interface will illuminate. RS232 Rx and Tx and RS485 A and B (pins 5, 6, 8 and 9) are referenced to the RS232/RS485 GND (pin 7). A connection should be made between pin 7 and the reference or common connection of the RS232 serial port or RS485 bus. Pin 1 2 3 4 5 6 7 8 9 E / 11819 / A Connection Vs (+5 VDC) GND (0 V) 0...5 V GND (0 V) 0...5 V Signal RS232 Rx RS232 Tx RS232/RS485 GND (0 V) RS485 A (+) RS485 B (-) Care should be taken when connecting the RS485 A and B connections to your system. The EIA-485 signalling specification states that signal A is the inverting or '-' pin and signal B is the non-inverting or '+' pin. This is in conflict with the A and B naming used by a number of differential transceiver manufacturers, including the transceiver used in the ZBXYO interface. Therefore always ensure the ‘+’ of the ZBXYO interface is connected to the ‘+’ input of the RS485 Bus and the ‘-’ of the ZBXYO interface is connected to the ‘-’ input of the RS485 Bus. 1/6 www.first-sensor.com www.sensortechnics.com ZBXYO Series Evaluation interface board for XYO optical oxygen sensors PERFORMANCE CHARACTERISTICS (At ambient conditions, TA=20 °C, PA=1013 mbar. Following extreme temperature fluctuations, re-calibration may be required.) Characteristics Oxygen measuring range Resolution Min. ppO2 partial pressure 0 O2 concentration (XYO...P) 0 D IG IT A L O U T P U T ppO2 partial pressure O2 concentration (XYO...P) A NA L OG OUTP UT Resolution Typ. Max. Unit 300 25 mbar %O2 0.1 0.01 mbar % 0.01 V RS232 OUTPUT RS232 setup The following setup should be used when using the RS232 interface. Baudrate Flow Control Parity Stop bits Data Length 9600 None None One 8 bits RS232 command set All RS232 communication is performed using ascii characters, the table shows the legal characters for each description block. There are three modes available: Poll Mode, Stream Mode and Off Mode. Description block Legal character(s) H ex <Command> "M", "O", "%", "T", "P", "A", "#", "e" 0x4D, 0x4F, 0x25, 0x54, 0x50, 0x41, 0x23, 0x65 <Argument> " 0" – " 9" 0x30 – 0x39 <Separator> "" 0x20 <Terminator> "\r\n" 0x0D, 0x0A Poll Mode (M 1) Each request is built using a combination of the description blocks. A typical arrangement will be one of the following formats: <Command><Terminator> <Command><Separator><Argument><Terminator> Each response will be in the following format: <Command><Separator><Argument><Terminator> E / 11819 / A 2/6 www.first-sensor.com www.sensortechnics.com ZBXYO Series Evaluation interface board for XYO optical oxygen sensors Command description Description of all commands and the valid arguments that can be applied to the interface when in Poll Mode (M1). All commands are case sensitive. Command Description Arguments R esp o n se "M" Output Mode 0=Stream "M xx\r\n" 1=Poll where xx equals the Argument of the command "O" Request current ppO2 value N/a "O xxxx.x\r\n" where xxxx.x equals the ppO2 in mbar "% " Request current O2 value N/a "% xxx.xx\r\n" (only valid with XYO...P. where xxx.xx equals the O2 in % Otherwise returns "- - - - - -") " T" Request current temperature inside N/a "T yxx.x\r\n" sensor where y equals the sign '-' or '+' and xx.x equals the temperature in °C "P" Request current barometric pressure N/a "P xxxx\r\n" (only valid with XYO...P. Where xxxx equals the pressure in mbar Otherwise returns "- - - - - -") " e" Sensor status N/a "e 0000\r\n" = Sensor Status Good "e xxxx\r\n" = Any other response contact First Sensor for advice. "A" Request all values N/a See section Stream Mode (M 0) (see above: O, T, P, % and e) " #" Sensor information 0=Date of manufacture "# 0YYYY00DDD\r\n" (DDD=day of the year) 1=Serial number "# xxxxx xxxxx\r\n" 2=Software revision "# xxxxx\r\n" Example 1 Request: current ppO2 value Response: 210.3 mbar Legal characters Hex "O\r\n" "0x4F 0x0D 0x0A" "0x4F 0x20 0x30 0x32 0x31 0x30 0x2E 0x33 0x0D 0x0A" "O 0210.3\r\n" Example 2 Request: streaming mode Response: streaming mode Legal characters Hex "M 0\r\n" "0x4D 0x20 0x30 0x0D 0x0A" "M 00\r\n" "0x4D 0x20 0x30 0x30 0x0D 0x0A" Error codes When a request has been unsuccessfully received, an error code may appear in a response format. Response Description Possible cause Action "E 00\r\n" RS232 Receiver Overflow No <Terminator> Check RS232 setup, confirm correct received before overflow termination. "E 01\r\n" Invalid Command Unrecognised Check command is valid. Check command <Command> received is upper Case "M" instead of "m". "E 02\r\n" Invalid Frame Incorrect character in Check correct separator is used. frame <Separator> "E 03\r\n" Invalid Argument <Argument> not allowed Check Argument is no longer than 6 or in limits characters. Check Argument is within limits. Check Argument is available for command. Stream Mode (M 0) By default stream mode is initiated on sensor power-up and will supply an output string approximately once every second. This provides the data for ppO2 , Temperature, Pressure, %O2 and Sensor Status. The format and equivalent block description is as follows: "O xxxx.x T yxx.x P xxxx % xxx.xx e xxxx\r\n" <Command><Separator><Argument><Separator> ... <Command><Separator><Argument><Terminator> E / 11819 / A 3/6 www.first-sensor.com www.sensortechnics.com ZBXYO Series Evaluation interface board for XYO optical oxygen sensors RS485 MODBUS OUTPUT RS485 Modbus setup The modbus interface is configured using the following setup: Modbus mode Address Baudrate Parity Stop bits RTU One 9600 None One Modbus registers Name ppO2 Register address Register type 0x7531 Input register Temperature 0x7532 Input register O2 0x7533 Input register Pressure 0x7534 Input register Sensor status 0x7535 Input register S en so r d ay S e n s o r ye ar Sensor ID 0 Sensor ID 1 Address 0x7536 0x7537 0x7538 0x7539 0x9C41 Input register Input register Input register Input register Holding register Baudrate 0x9C42 Holding register Parity 0x9C43 Holding register Stop bits 0x9C44 Holding register Communication settings 0x9C45 Holding register 0...5 V output representation 0x9C46 Holding register Description = x/10 ppO2 (where: 0 = 0 ppO2, 2105 = 210.5 ppO2 ) = x (signed) / 10 C (where: 65231 = -30.5 C , 201 = 20.1 C ) = x/ 100 (where: 0 = 0 %, 2070 = 20.70 % ) = x mBar (where: 1017 = 1017 mbar) 0 = Sensor status good Anything else contact First Sensor for guidance Day number of manufacture Year of manufacture Serial number 0 Serial number 1 Range = 1 to 247 (0x01 to 0xF7) Default = 1 0 (0x00) = 2400 1 (0x01) = 4800 2 (0x02) = 9600 (Default) 3 (0x03) = 19200 4 (0x04) = 38400 5 (0x05) = 57600 6 (0x06) = 115200 0 (0x00) = None (Default) 1 (0x01) = Odd 2 (0x02) = Even 0 (0x00) = 1 (Default) 1 (0x01) = 2 0 (0x00) = No action 1 (0x01) = Reset and apply changes to Modbus communication settings (see note 1) 0 (0x00) = Auto Detect (Default) 1 (0x01) = ppO2 2 (0x02) = O2 % (see note 2) Specification notes: 1. If any changes are made to the holding registers 0x9C41 to 0x9C44 the changes will not be applied until 0x9C45 is set to “1”. At this point, if the changes made are valid, the new settings will be committed to memory and communication will be lost until the RS485 master is reconfigured to the same settings. 2. The 0...5 V analog output is default to represent the variant of the sensor connected to the interface, so if the sensor attached is a ppO2 variant (XYOM300N) the 0...5 V output will represent 0...300 mbar or if the sensor attached is an O2% variant (XYOM300P) the 0...5 V output will represent 0...25 % O2. However when the attached sensor is an O2% variant the auto detect setting can be overridden so the 0...5 V output can represent either ppO2 or O2%. This feature is not compatible with the ppO2 variant so if this register is changed to “2” in this instance the 0...5 V output will remain at 0 V. E / 11819 / A 4/6 www.first-sensor.com www.sensortechnics.com ZBXYO Series Evaluation interface board for XYO optical oxygen sensors ANALOG OUTPUT ppO2 variant (with XYOM300N sensor) The current ppO2 level can be calculated as follows: ppO 2 = 300 300 ⋅V = ⋅ V = 60 ⋅ V Vmax 5 Where: ppO2 = Current ppO2 in mbar Vmax = 5 V V = Analog voltage on the signal output ppO2 examples Signal output (V) 0 3.5 5 ppO2 (mbar) 0 210 300 O2% variant (with XYOM300P sensor) The current O2% level can be calculated as follows: O2 % = 25 25 ⋅V = ⋅V = 5⋅V Vmax 5 Where: O2% = Current O2 concentration (%) Vmax = 5 V V = Analog voltage on the signal output ppO2 examples Signal output (V) 0 3.5 5 E / 11819 / A O2 (% ) 0 17.5 25 5/6 www.first-sensor.com www.sensortechnics.com ZBXYO Series Evaluation interface board for XYO optical oxygen sensors OUTLINE DRAWING dimensions in mm ORDERING INFORMATION Series ZB X YO Evaluation interface board for XYO optical oxygen sensors* * Please order the XYO sensor separately First Sensor reserves the right to make changes to any products herein. First Sensor does not assume any liability arising out of the application or use of any product or circuit described herein, neither does it convey any license under its patent rights nor the rights of others. E / 11819 / A 6/6 www.first-sensor.com www.sensortechnics.com