GSA-M Series Single Turn Modbus Absolute Encoder

short description:

GSA-M Series encoder is a single turn bus-based Modbus absolute encoder, it can provide max 16bits sing-trun resolution, with options of housing Dia.:38,50,58mm; Solid/hollow Shaft Diameter:6,8,10mm, Output Code: Binary, Gray, Gray Excess, BCD; Supply Voltage:5v,8-29v; MODBUS is a request/reply protocol and offers services specified by function codes. MODBUS function codes are elements of MODBUS request/reply PDUs. The objective of this document is to describe the function codes used within the framework of MODBUS transactions. MODBUS is an application layer messaging protocol for client/server communication between devices connected on different types of buses or networks.

Housing Diameter:38,50,58mm;

Solid/hollow Shaft Diameter:6,8,10mm;

Resolution:Max.16bits;

Supply Voltage:5v,8-29v;

Interface:Modbus

Output Code:Binary, Gray, Gray Excess, BCD

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Product Detail

1. Basic Product Parameters

Parameter	Details/Options
Model	GSA-M Series Single Turn Modbus Absolute Encoder
Housing Diameter	38 mm, 50 mm, 58 mm
Shaft Diameter	6 mm, 8 mm, 10 mm (Solid/Hollow)
Resolution	Single turn, up to 16-bit
Output Code	Binary, Gray, Excess Gray, BCD
Interface	Modbus (RS-485)
Supply Voltage	5V; 8–29V
Maximum Frequency	300 kHz

2. Electrical Data

Output Format	Consumption Current	Load Current	VOH	VOL
Open Collector	≤80 mA	40 mA	≥ Vcc × 70%	≤ 0.4 V
Voltage Output	≤80 mA	40 mA	≥ Vcc – 2.5 V	≤ 0.4 V
Line Driver	≤150 mA	60 mA	≥ 3.4 V	≤ 0.4 V
Push Pull	≤80 mA	40 mA	≥ Vcc – 1.5 V	≤ 0.8 V

3. Mechanical Data

Parameter	Value
Start Torque	4 × 10⁻³ N·m
Maximum Axial Load	29.4 N
Maximum Radial Load	19.6 N
Maximum Speed	3000 rpm
Weight	160 – 200 g

4. Environmental Data

Parameter	Range
Operating Temp.	-30°C ~ 80°C
Storage Temp.	-40°C ~ 80°C
Protection Grade	IP54

5. Modbus Communication Parameters

Parameter	Details
Transmission	RS-485
Address Range	1–254 (Default address: 01H)
Baud Rate	4800, 9600 (default), 19200, 38400
Transmission Media	STP
Data Frame Format	1 start bit, 8 data bits, 1 even parity bit, 1 stop bit; no flow control
Protocol	Modbus (Request/Response mode)

6. Modbus Message Format

Function Code	Function Description	Master Request Format	Slave Response Format	Example
03H	Read Position Value	Address \| 03H \| Parameter Address \| Data Length \| Check Code	Address \| 03H \| Byte Length \| Parameter Value \| Check Code	Master Example: 01H 03H 00H 00H 00H 02H C4H 0BH Slave Example: 01H 03H 04H 01H F4H 00H 01H 7BH FDH
10H	Preset Current Position	Address \| 10H \| Parameter Address \| Data Length \| Byte Length \| Parameter Value \| Check Code	Address \| 10H \| Parameter Address \| Data Length \| Check Code	Master Example: 01H 10H 00H 4AH 00H 02H 04H 00H 00H 00H 00H 77H E0H Slave Example: 01H 10H 00H 4AH 00H 02H 60H 1EH
06H	Write Parameter Value	Address \| 06H \| Parameter Address \| Parameter Value \| Check Code	Address \| 06H \| Parameter Address \| Parameter Value \| Check Code	Example – Change ID: Master: 01H 06H 00H 44H 00H 02H 48H 1EH Slave: 02H 06H 00H 44H 00H 02H 48H 2DH

7. Parameter Settings & Register Allocation

Parameter Name	Register Address	Length	Data Description	Note
Change Encoder ID	0044H	0001H	High byte fixed at 00H, low byte is the new ID	Takes effect after power cycling
Baud Rate Setting	0045H	0001H	High byte fixed at 00H, low byte is the baud rate code	Codes: 01: 4800bps; 02: 9600bps; 03: 19200bps; 04: 38400bps
Counting Direction	0046H	0001H	High byte fixed at 00H, low byte is the counting direction code	00: Clockwise (increasing); 01: Counterclockwise (decreasing)
Preset Current Position	004AH	0002H	Four bytes (from high to low) representing the current position value	Preset value must not exceed the physical limit

8. Parameter Change Examples

Example	Master Send Message	Slave Response Message	Description
a. Change Encoder ID (01H → 02H)	01H 06H 00H 44H 00H 02H 48H 1EH	02H 06H 00H 44H 00H 02H 48H 2DH	Using register 0044H
b. Change Baud Rate (to 38400bps, code 04H)	01H 06H 00H 45H 00H 04H 99H DCH	01H 06H 00H 45H 00H 04H 99H DCH	Using register 0045H
c. Change Counting Direction (to Counterclockwise, code 01H)	01H 06H 00H 46H 00H 01H A9H DFH	01H 06H 00H 46H 00H 01H A9H DFH	Using register 0046H
d. Preset Current Position (00000000H)	01H 10H 00H 4AH 00H 02H 04H 00H 00H 00H 00H 77H E0H	01H 10H 00H 4AH 00H 02H 60H 1EH	Using register 004AH

9. Selection Process (Five Steps)

Step	Description
1	If you already use encoders from other brands, provide the brand and model information for equivalent replacement suggestions.
2	Choose the encoder type: Incremental, Absolute, Draw Wire Sensors, or Manual Pulse Generator.
3	Select the output format (for incremental: NPN/PNP/LINE DRIVER/PUSH PULL) or the interface (e.g., Modbus, SSI, BISS, etc.).
4	Choose the encoder resolution (Incremental: up to 50000 ppr; Absolute: up to 29-bit).
5	Select the housing diameter and shaft diameter of the encoder.

10. Equivalent Replacement Products Reference

Brand	Example Models
Omron	E6A2-CS3C, E6A2-CS3E, E6A2-CS5C, E6A2-CW3C, E6A2-CW3E, E6A2-CW5C, E6A2-CWZ3C, E6A2-CWZ3E, E6A2-CWZ5C
Koyo	TRD-MX, TRD-2E/1EH, TRD-2T, TRD-2TH, TRD-S, TRD-SH, TRD-N, TRD-NH, TRD-J, TRD-GK, TRD-CH Series
Autonics	E30S, E40S, E40H, E50S, E50H, E60S, E60H

11. Packaging Details

Item	Description
Packaging	Standard export packaging or customized per buyer's requirements

12. FAQ and Other Information

Content	Details
Delivery Time	Shipment within one week via DHL or other specified logistics after full payment
Payment Methods	Bank Transfer, Western Union, Paypal
Quality Control	Inspected by a professional quality control team with over 10 years of experience
Technical Support	Supported by a professional technical team, including protocols such as Profinet, EtherCAT, Modbus-TCP, and Powerlink
Certifications	CE, ISO9001, RoHS; KC certification in progress
After-sales Policy	1-year warranty and lifetime technical support
Contact	Terry_Marketing@gertechsensors.com (also available via WhatsApp or WeChat for instant messaging)