YOKOGAWA YS100 series instrument

YOKOGAWA YS100 series instrument

The YS100 series instruments (including YS150/YS170/YS131/YS135/YS136 models) support RS-485 (option code/A31) and DCS-LCS (option code/A32) communication functions. The former can be interconnected with multiple monitoring computers (up to 16 units, communication distance ≤ 1200m), while the latter can be connected to the Yokogawa CENTUM-XL/μ XL DCS system (up to 24 units/EFCS); The core communication parameters include baud rate of 1200-9600bps, half duplex mode, ASCII 8-bit encoding, support for data read and write (DG/DP commands), watchdog timer settings, and other functions. The parameters need to be configured through the front-end panel to adapt to the monitoring and operation requirements in industrial process control, while providing a comprehensive error handling mechanism and programming examples.

Core communication specifications

（1） RS-485 communication specifications

Category specific parameters

Communication interface RS-485 five signals: SD (A), SD (B), RD (A), RD (B), SG (signal ground)

Communication protocol without protocol (command response format), asynchronous operation

Transmission parameter baud rate: 1200/2400/4800/9600bps; Stop position: 1/2 position; Parity check: None/Odd/Even

Data format ASCII 8-bit encoding, single block structure, maximum block length of 220 bytes (including CR/LF)

Up to 16 instruments can be connected (multi station connection), with a communication distance of ≤ 1200m

Wiring requirements recommend shielded twisted pair cables (0.5-1.25mm ²), supporting 2-wire/4-wire wiring, with 120 Ω± 1% terminal resistors at both ends

（2） DCS-LCS Communication Specification

Category specific parameters

Adaptation System Yokogawa Distributed Control System (CENTUM-XL, μ XL)

The connection method is to connect the LCS circuit communication card to the DCS on-site control unit

The maximum connection capacity is 8 instruments/LCS cards, 3 LCS cards/MFCU, 24 instruments/MFCU, and 120 instruments/EFCS

Wiring requirements: KS4 cable (maximum length 100m), SCCD shielded twisted pair cable

The core function of YS100 is registered as an internal instrument of DCS, which can be monitored, operated, and parameter set through the DCS operator station

Installation and parameter configuration

（1） Terminal allocation

Terminal number RS-485 communication function DCS-LCS communication function

14 Signal Ground (SG) LCS+, LCS-

Send Data A (SD (A))-

16 Send Data B (SD (B))-

17 Receive Data A (RD (A))-

18 Receive Data B (RD (B))-

FG (GND) shielding layer shielding layer

（2） Parameter configuration (front-end panel CONFIG1 menu)

Configuration item function description default value optional range

SET configuration enable/disable INHB INHB (disable), ENBL (enable)

COMM communication function display -485 (RS-485), LCS (DCS-LCS)

COMWR communication write enable ENBL ENBL (allowed), INHB (prohibited)

ADRS RS-485 instrument address 1-16

STBIT RS-485 stop bits 1, 2

PAR RS-485 parity check NO NO, ODD odd, EVENT even

BPS RS-485 baud rates 1200, 2400, 4800, 9600bps

（3） Computer mode settings

Mode Type Applicable Model Function Description

SPC mode YS150/YS170 monitoring system sends set values

DDC mode YS150/YS170 monitoring system sends operation signals

Switch between backup mode YS150/YS170 in case of monitoring system failure (BUA automatic/BUM manual)

Communication functions and commands

（1） RS-485 core command

Example of Command Function Format

DG (Data Reading) reads instrument parameters (PV/SV/MV, etc.) and sends: DG 02 03 PV1 SV1 MV1 [CR] [LF]; Response: DG 02 03 50.0 30.0 65.5 [CR] [LF]

DP (Data Write) sets instrument parameters (alarm values/set values, etc.) and sends: DP 02 03 PH1 98.0 PL1 5.0 [CR] [LF]; Response: DP 02 03 98.0 5.0 [CR] [LF]

Set timeout time in WDT (watchdog setting) DDC/SPC mode and send: WDT 01 0060 [CR] [LF]; Response: WDT 01 0060 [CR] [LF]

（2） Communication data type (core commonly used)

Data Type Name Applicable Model Range Read/Write Permissions

PV1/PV2 process variable series -6.3~106.3% read-only

SV1/SV2 set values YS150/YS170/YS135-6.3~106.3% can be written (specific mode)

MV1/MV2 operation variables YS150/YS170/YS136-6.3~106.3% writable (specific mode)

PH1/PL1 high and low limit alarm set values for the entire series -6.3~106.3% can be written

PRCA process alarm status series 8-bit binary (0=normal/1=fault) read-only

LS1/LS2 operating modes YS150/YS170 MAN/OUT/CAS/SPC/DDC can be written

（3） DCS-LCS communication correspondence

YS100 DCS Instrument Model Core Monitored Parameters

YS150 SLPC PV, SV, MV, P (proportional band), I (integral time), D (derivative time)

YS170 SLPC PV、SV、MV、 Program control parameters, alarm status

YS135 SMST-111 PV、SV、 High and low limit alarm setting values

YS136 SMST-121 PV、MV、 Upper and lower limits of manipulated variables

Error Handling and Programming Examples

（1） Common types of errors and their handling

Measures for handling error type phenomena

Communication parameters do not match, instrument does not respond, unified computer and instrument baud rate, parity check and other parameters

Address error: The instrument is unresponsive. Please confirm the instrument address (1-16) to avoid duplicate allocation

The response message is too long and returns an error code @ 100. Reduce the amount of data read in a single attempt and ensure that the message is ≤ 220 bytes

Return the corresponding error code for syntax errors (such as @ 011=invalid command). Check the command format, parameter names, and data format

（2） Programming Example

Provide an IBM-PC BASIC program example for reading data from YS100 instrument PV1, SV1, and MV1 at address 01. The core steps include port configuration, command sending, response receiving, and display.

User Program Example (YS170 Proportional Controller)

Proportional control is achieved through DCS-LCS communication, using BS (corresponding to P1 parameter) to set the proportional coefficient, X2 as the cascaded input value, Y4/Y5 as the communication register feedback intermediate calculation result, and finally outputting CSV1 as the set value to drive the control loop.