Modbus:

Modbus Slave Address Table of the RM Robotic Arm

The RealMan robotic arm supports the Modbus slave, which is available on both Modbus-RTU and Modbus-TCP, and all the slaves share the address table and functions.

• Modbus-TCP: Use the Ethernet port or WiFi for communication, with parameters set as follows: IP address: IP address of the robotic arm; port number: 502; and device ID: 1.
• Modbus-RTU: Use the controller 485 port for communication, with parameters set as follows: baud rate: 9600, 115200, or 460800; and slave address: 01.

Note: When users customize the register addresses, it is preferred to use the 3000 or later to prevent conflicts between the address occupation caused by program upgrades and the user-defined function.

1. Address description

1.1 Coil

Address	Function	Value Description
0	Digital IO1 mode	0: input; 1: output
1	Digital IO1	0: low; 1: high
2	Digital IO2 mode	0: input; 1: output
3	Digital IO2	0: low; 1: high
4	Digital IO3 mode	0: input; 1: output
5	Digital IO3	0: low; 1: high
6	Digital IO4 mode	0: input; 1: output
7	Digital IO4	0: low; 1: high
48	Joint1 enabling state	0: disable; 1: enable (control temporarily unavailable)
49	Joint2 enabling state	0: disable; 1: enable (control temporarily unavailable)
50	Joint3 enabling state	0: disable; 1: enable (control temporarily unavailable)
51	Joint4 enabling state	0: disable; 1: enable (control temporarily unavailable)
52	Joint5 enabling state	0: disable; 1: enable (control temporarily unavailable)
53	Joint6 enabling state	0: disable; 1: enable (control temporarily unavailable)
54	Joint7 enabling state	0: disable; 1: enable (control temporarily unavailable)

1.2 Discrete input

Address	Function	Value Description
0	Digital IO1 mode	0: input; 1: output
1	Digital IO1	0: low; 1: high
2	Digital IO2 mode	0: input; 1: output
3	Digital IO2	0: low; 1: high
4	Digital IO3 mode	0: input; 1: output
5	Digital IO3	0: low; 1: high
6	Digital IO4 mode	0: input; 1: output
7	Digital IO4	0: low; 1: high

1.3 Holding register

For the address ranges from 2000 to 2200 (including), the automatic saving is realized after the register powers off.

Address	Function	Value Description
0	VOUT Output voltage	0: 0 V; 2: 12 V; 3: 24 V
1	Number of the given program, range: 1−100. The data is cleared after the controller runs the program, and it is set to -1 if the run fails.	Input: 1−100 Output: 0: success; -1: failure
2	Given running speed, range: 1−100. After register 1 starts the robotic arm program, the speed takes effect, and the data is cleared	Speed range: 1−100
3	Control program, range: 1−3. The data is cleared after being detected by the controller.	1: emergency stop; 2: pause; 3: continuation
1−149	Reserved
150	Two high bytes of motion position parameter 1
151	Two low bytes of motion position parameter 1
152	Two high bytes of motion position parameter 2
153	Two low bytes of motion position parameter 2
154	Two high bytes of motion position parameter 3
155	Two low bytes of motion position parameter 3
156	Two high bytes of motion position parameter 4
157	Two low bytes of motion position parameter 4
158	Two high bytes of motion position parameter 5
159	Two low bytes of motion position parameter 5
160	Two high bytes of motion position parameter 6
161	Two low bytes of motion position parameter 6
162	Two high bytes of motion position parameter 7
163	Two low bytes of motion position parameter 7
164	Two high bytes of motion position parameter 8
165	Two low bytes of motion position parameter 8
166	Two high bytes of motion position parameter 9
167	Two low bytes of motion position parameter 9
168	Two high bytes of motion position parameter 10
169	Two low bytes of motion position parameter 10
170	Two high bytes of motion position parameter 11
171	Two low bytes of motion position parameter 11
172	Two high bytes of motion position parameter 12
173	Two low bytes of motion position parameter 12
174−179	Reserved
180	Motion type	1: MoveJ; 2: MoveJ_P; 3: MoveL; 4: MoveC
181	Motion command: 1: start; 2: stop
182	Speed percentage	1−100
183	Two high bytes of the blend radius
184	Two low bytes of the blend radius
185	Loop count
228	Get and set the current collision stage. This address can be used to get and set the current collision stage. Only the stages consistent with those in the JSON protocol are supported. If the value is beyond the range, the maximum stage 8 is automatically applied	Collision stage: 0−8
229	Real-time speed adjustment of motion	1-100 speed ratio

1.4 Input register

Address	Function	Value Description
0	End effector position X, in mm	Unsigned integer and two's complement for negative numbers
1	End effector position Y, in mm	Unsigned integer and two's complement for negative numbers
2	End effector position Z, in mm	Unsigned integer and two's complement for negative numbers
3	End effector orientation RX, in rad	Unsigned integer and two's complement for negative numbers
4	End effector orientation RY, in rad	Unsigned integer and two's complement for negative numbers
5	End effector orientation RZ, in rad	Unsigned integer and two's complement for negative numbers
6	Joint1 angle, in °	Unsigned integer and two's complement for negative numbers
7	Joint2 angle, in °	Unsigned integer and two's complement for negative numbers
8	Joint3 angle, in °	Unsigned integer and two's complement for negative numbers
9	Joint4 angle, in °	Unsigned integer and two's complement for negative numbers
10	Joint5 angle, in °	Unsigned integer and two's complement for negative numbers
11	Joint6 angle, in °	Unsigned integer and two's complement for negative numbers
12	Joint7 angle, in °	Unsigned integer and two's complement for negative numbers
13	Joint1 current, in mA	Unsigned integer and two's complement for negative numbers
14	Joint2 current, in mA	Unsigned integer and two's complement for negative numbers
15	Joint3 current, in mA	Unsigned integer and two's complement for negative numbers
16	Joint4 current, in mA	Unsigned integer and two's complement for negative numbers
17	Joint5 current, in mA	Unsigned integer and two's complement for negative numbers
18	Joint6 current, in mA	Unsigned integer and two's complement for negative numbers
19	Joint7 current, in mA	Unsigned integer and two's complement for negative numbers
20	Joint1 voltage, in V	Unsigned integer and two's complement for negative numbers
21	Joint2 voltage, in V	Unsigned integer and two's complement for negative numbers
22	Joint3 voltage, in V	Unsigned integer and two's complement for negative numbers
23	Joint4 voltage, in V	Unsigned integer and two's complement for negative numbers
24	Joint5 voltage, in V	Unsigned integer and two's complement for negative numbers
25	Joint6 voltage, in V	Unsigned integer and two's complement for negative numbers
26	Joint7 voltage, in V	Unsigned integer and two's complement for negative numbers
27	Joint1 temperature, in °C	Unsigned integer and two's complement for negative numbers
28	Joint2 temperature, in °C	Unsigned integer and two's complement for negative numbers
29	Joint3 temperature, in °C	Unsigned integer and two's complement for negative numbers
30	Joint4 temperature, in °C	Unsigned integer and two's complement for negative numbers
31	Joint5 temperature, in °C	Unsigned integer and two's complement for negative numbers
32	Joint6 temperature, in °C	Unsigned integer and two's complement for negative numbers
33	Joint7 temperature, in °C	Unsigned integer and two's complement for negative numbers
34	System error code, refer to the JSON protocol for details
35	Heart rate (+1 per second)
36	Position X, in mm	Float
38	Position Y, in mm	Float
40	Position Z, in mm	Float
42	Orientation RX, in rad	Float
44	Orientation RY, in rad	Float
46	Orientation RZ, in rad	Float
48	Joint1 angle, in °	Float
50	Joint2 angle, in °	Float
52	Joint3 angle, in °	Float
54	Joint4 angle, in °	Float
56	Joint5 angle, in °	Float
58	Joint6 angle, in °	Float
60	Joint7 angle, in °	Float
99	Program running state	0: not started; 1: running; 3: paused
100	Number of program lines of the robotic arm
101	ID of the currently running program, 0: no trajectory saved
200	Joint1 error code	Refer to the JSON protocol for details
201	Joint2 error code	Refer to the JSON protocol for details
202	Joint3 error code	Refer to the JSON protocol for details
203	Joint4 error code	Refer to the JSON protocol for details
204	Joint5 error code	Refer to the JSON protocol for details
205	Joint6 error code	Refer to the JSON protocol for details
206	Joint7 error code	Refer to the JSON protocol for details
300	Motion in position along planned trajectory	0: motion not in position; 1: motion in position; 2: planning failed
301	Trajectory planning state	0: no planning; 1: planning
302	Emergency Stop Status	0 indicates entering emergency stop

2. Data conversion

The following is a conversion from the register value to the angle in float type:

    float fun(quint16 H,quint16 L)
    {
        FloatTo4Bytes uValue;
        uValue.Byte[3] = (H >> 8) & 0xFF;
        uValue.Byte[2] = H & 0x00FF;
        uValue.Byte[1] = (L >> 8) & 0xFF;
        uValue.Byte[0] = L & 0x00FF;
        return uValue.a;
    }

3. Demo of motion control

For MoveJ, the demo of holding register addresses and target joint angles is as follows:

Address	150	151	152	153	154	155	156	157	158	159	160	161
H(0x)	4374	52f2	41c6	4bc7	4443	0d50	3dae	147b	bf72	f1aa	4040	72b0
Data	-11.252		-0.921		-28.0674		17.812		-26.277		-13.981

Description: Register addresses 150−161 store the target angles of joints 1−6, and two adjacent register addresses store a joint angle, in float type and with high bits in front. Conversion from the angle in float type to the register value:

void fun(float value, quint16 *H, quint16 *L)
{
    quint8 buf[4] = {0};
    memcpy(buf, &value, sizeof(float));
    *H = ((quint16)buf[3]<<8)|buf[2];
    *L = ((quint16)buf[1]<<8)|buf[0];
}

Demo of MoveJ holding register addresses and motion control parameters:

Address	180	181	182	183	184	185
D	1	1	50	0	0	1
Type	Motion type	Motion command	Speed	Blend radius	Blend radius	Loop

Description:

1. Address 180: current motion type, 0: None; 1: MoveJ; 2: MoveJ_P; 3: MoveL; 4: MoveC;
2. Address 181: motion command, 1: start; 2: stop;
3. Address 182: speed percentage, 0−100;
4. Address 183: high bits of blend radius;
5. Address 184: low bits of blend radius;
6. Address 185: Loop count (for MoveC only).