YOKOGAWA YS100 series instrument

YS170 (Programmable Controller) SLPC supports PV/SV/MV read and write, program control parameter adjustment, and alarm status monitoring

YS135 (SV setting automatic/manual station) SMST-111 supports PV monitoring, SV setting, and high/low limit alarm configuration

YS136 (MV setting automatic/manual station) SMST-121 supports PV monitoring, MV setting, and upper and lower limit configuration of operating variables

Installation and wiring specifications

（1） Terminal allocation

The communication terminal of YS100 series instruments is located on the back of the equipment, and can be viewed after removing the terminal cover. The terminal number is marked on the sealing parts and terminal cover on both sides of the chassis. The core communication terminals are assigned as follows:

Terminal Number RS-485 Communication Function DCS-LCS Communication Function Remarks

14 Signal Ground (SG) LCS+, LCS - dual function terminal, switch usage according to communication options

15 Send Data A (SD (A)) - Used only for RS-485 communication

16 Send Data B (SD (B)) - Used only for RS-485 communication

17 Receive Data A (RD (A)) - Used only for RS-485 communication

18 Receive Data B (RD (B)) - Used only for RS-485 communication

FG (GND) shielding layer grounding shielding layer grounding forced grounding, used for anti-interference

Note: The voltage definition of terminals A and B follows the EIA standard: when the signal is "mark" and VA<VB, the corresponding terminal status is OFF or 1; When the signal is "space" and VA>VB, the corresponding terminal status is ON or 0.

（2） RS-485 communication wiring

1. Four wire wiring system

Applicable scenarios: Bidirectional communication scenarios that require simultaneous sending and receiving, with higher communication stability;

Wiring requirements: Use 4-core shielded twisted pair cables to connect SD (A), SD (B), RD (A), and RD (B) respectively. The signal ground (SG) and shielding layer (FG) should be grounded together to avoid common mode interference;

Terminal resistance: Connect 120 Ω terminal resistors between SD (A) - SD (B) and RD (A) - RD (B) on the monitoring computer side and the farthest instrument side, respectively.

2. Two wire wiring system

Applicable scenarios: scenarios with low communication speed requirements and sensitive wiring costs;

Wiring requirements: Use 2-core shielded twisted pair, short-circuit SD (A) and RD (A), short-circuit SD (B) and RD (B), and connect them to the bus. Signal ground and shielding layer ground;

Terminal resistor: Connect a 120 Ω terminal resistor between the short circuited terminals at both ends of the bus.

3. Wiring precautions

Avoid parallel laying with power cables. If crossing is necessary, maintain a 90 ° vertical crossing to reduce electromagnetic interference;

The shielding layer needs to be grounded at one end (recommended to be grounded on the monitoring computer side) to avoid the formation of a grounding loop at both ends;

The cable length cannot exceed 1200m, and if it exceeds this limit, a signal amplifier (compatible with RS-485 protocol) must be used;

When multiple instruments are connected, a bus topology structure is used, and star connections are prohibited to avoid signal reflection.

（3） DCS-LCS communication cabling

1. Core wiring structure

Link composition: DCS field control unit (such as MFCU) → LCS communication card → TE08 terminal block → YS100 instrument, connected to SCCD twisted pair cable through KS4 cable;

Wiring distance: The maximum length of a single section of KS4 cable is 100m. The length of the SCCD twisted pair between the TE08 terminal block and the instrument should be adjusted according to the site layout, and the total attenuation should be controlled;

Shielding requirement: The shielding layer of all communication cables must be connected to the shielding terminal (S) of TE08 terminal block to achieve unified grounding.

2. YS100 and TE08 terminal block wiring

Wiring method: Each YS100 instrument is connected to the LCS+and LCS - terminals of the TE08 terminal block through SCCD twisted pair cables. Terminal 17 corresponds to LCS+, and terminal 18 corresponds to LCS -;

Connection restriction: A single TE08 terminal block can connect up to 8 YS100 instruments, and multiple instruments can be connected in parallel on the same LCS+or LCS - bus.

Communication parameter configuration

（1） Configure entrance and basic parameters

1. Configuration method

The communication parameters are set through the engineering panel group (CONFIG1 menu) on the instrument front-end panel, and only the enable/disable of the terminal resistor needs to be operated through the JP1 jumper on the RS-485 communication board (hardware configuration).

2. Core configuration parameters (CONFIG1 menu)

Line number display item function description default value optional range remark

1 SET configuration enable/disable INHB (disable) INHB, ENBL (enable) must be set to ENBL to modify other parameters

5 COMM communication function display -485 (RS-485), LCS (DCS-LCS) automatically recognizes installed communication options without manual setting

When COMWR communication is enabled with ENBL (allowed) and INHB (prohibited), instrument parameters cannot be modified through communication