Communications-Protocol-Keling

Communications Protocol Keling

TH MODBUS USER INSTRUCTIONS

1, The instrument RS485 communication BPS is fixed at 9600 bits/s, start bit=1, data bit=8, stop bit=2, starting and ending time >5ms.

2, The format of the data reading and writing is same as standard Modbus protocol. Definition as follows:

Request: 01 03 238(00EE) 0002 42046 (A43E) ADD COM PV1 Counts CRC

Response: 01 03 04 6D96 49F3 7166 ADD COM Counts PV1 CRC

PV1 = 6D96 49F3 = 6D96.49F3H = 6D96H+0. 49F3H=28054.28890

When Max bit is ¡°1¡±, means negative, e.g.: PV1=ED9649F3= ED96.49F3H = -(6D96H+0.49F3H) = -28054.28890 ED96 bit 15=1 is negative, viz. -6D96H

3, When setting parameters, can read multi- parameters; when writing, can write 1 parameter only every time

4, Commands:

 02H: read digital value / discrete I/O parameters
 03H: read holding registers parameters
 06H: write single holding register parameter value
 10H: write multi holding registers parameters value
 41H: instrument calibration command 

• • (when appearing unused command, response errors.meassage

Parameter ¡°02H.41H command is not used in DS8 AND TCH SERIERS)

5, Communication parameters:

Factory setting Parameters Parameter address (HEX) Data numbers (bytes) Function Remark

 FLAG4 104 2 Read and write symbol Read only 
 MV 105 4 PID1 operating value output Read only 
 MV1 168 4 PID2 operating value output Read only 
 PV1 201 4 1st input measuring value  Read only 
 PV2 204 4 2nd input measuring value  Read only 
 SV 0000 4 Set control value R / W 

100 AL1 0004 4 Alarm 1 set value R / W 900 AL2 0008 4 Alarm 2 set value R / W 500 AL3 0012 4 Alarm 3 set value R / W 0£®0 cdB 0016 4 Cooling clearance R / W 0 AT 0019 2 Set Auto-tune R / W 000 LCK 0020 2 Set lock function R / W 0 MAN 0021 2 Set manual or auto manipulation R / W 001 ADD 0022 2 Set instrument communication address R / W 0£®0 PSV1 0024 4 PV1 correction value R / W 0£®0 PSV2 0028 4 PV2 correction value R / W 1£®0 HY1 0032 4 Alarm 1 hysteresis value R / W 0 AM1 0035 2 Alarm 1 mode setting R / W 1£®0 HY2 0036 4 Alarm 2 hysteresis value R / W 1 AM2 0039 2 Alarm 2 mode setting R / W 1£®0 HY3 0040 4 Alarm 3 hysteresis value R / W 2 AM3 0043 2 Alarm 3 mode setting R / W 3£®0 P 0044 4 PID 1 proportion band R / W 240 I 0048 4 PID 1 Integral time R / W 0£®0 D 0052 4 PID 1 differential coefficient time R / W 0 OUD 0055 2 PID 1 control direction R / W 1£®0 HYS 0056 4 PID 1 control function R / W 020 CTL 0059 2 PID 1 control cycle R / W 0£®0 OUTL 0060 4 PID1 MV output low limit R / W 100£®0 OUTH 0064 4 PID1MV output high limit R / W 0£®0 HUM 0068 4 PID 1 desiccant output limit R / W 5£®0 Pc 0072 4 PID 2 proportion band R / W 240 Ic 0076 4 PID 2 Integral time R / W 0£®0 Dc 0080 4 PID 2 differential coefficient time R / W 1 OUC 0083 2 PID 2 control direction R / W 020 C-t 0084 2 PID 2 control cycle R / W K type INP1 0085 2 1st Select input signals R / W 0.0 LSP 0088 4 1st input low limit display R / W 1200 USP 0092 4 1st input high limit display R / W 1 DP1 0095 2 Select decimal point for 1st input R / W 0 UNIt 0096 2 Select display unit for 1st input R / W

Sales@EmbeddedRF.com wrote: I know its an rs-485.