Hitachi SJ-PB(T) instruction manual Writing a two byte array parameter #2

CHAPTER5 OPERATING

In the request message the first two bytes are used for parameter identification. The first digit (7) denotes the function “Change parameter value (array word)” (refer to chapter 3.2). The second digit along with the second byte (3 and 93) indicates parameter number 916. Byte 3 (01) denotes sub-index in the array parameter, in this case “01” means the first index in the array. Bytes 7 and 8 (00 3D = 61dec) contains the parameter number that shall be mapped. This means that in the PZD3 place the read value of parameter A038 (Profibus parameter number 61dec) shall be transferred from the inverter to the master every bus-cycle.

In the response message, the first digit (4) indicates the function “Transfer parameter value (array word)”. Sub- index (01 00), value (00 3D in bytes 7 and 8) and parameter number (x3 94) are mirrored from the request. In the PZD3 field (word 7) the value (01 F4 = 500dec, 5.00 Hz) of “Jogging frequency” is transferred.

5.4.3 Writing a two byte array parameter #2

In this third example, we are configuring PZD3 to contain the value of parameter A004, “1st Maximum frequency” in the request from the master to the inverter. PPO2 is used. On Profibus parameter A004 corresponds to parameter number 62 (3Eh). This is configured with parameter number 915 (393h), “Assignment of PZD write word” (see also chapter 5.3.3 and 5.5).

Word

Request:

PLC->Inverter

Response:

Inverter->PLC

PKW				PZD
1	2	3	4	5	6	7	8	9	10
PKE	IND	PWE	PWE	STW	HSW	PZD3	PZD4	PZD5	PZD6
				ZSW	HIW
73 93	01 00	00 00	00 3E	04 7F	20 00	00 4B	00 00	00 00	00 00
43 93	01 00	00 00	00 3E	03 37	20 00	01 F4	00 00	00 00	00 00

In the request message the first two bytes are used for parameter identification. The first digit (7) denotes the function “Change parameter value (array word)” (refer to chapter 3.2). The second digit along with the second byte (3 and 93) indicates parameter number 915. Byte 3 (01) denotes sub-index in the array parameter, in this case “01” means the first index in the array. Bytes 7 and 8 (00 3E = 62dec) contains the parameter number that shall be mapped. In the PZD3 field (word 7) the value (00 4B = 75, 75 Hz) of “1st Maximum frequency” is transferred. That is, parameter A004 will be written with the value 75.

In the response message, the first digit (4) indicates the function “Transfer parameter value (array word)”. Sub- index (01 00), value (00 3E in bytes 7 and 8) and parameter number (x3 93) are mirrored from the request. As can be seen in word 7 (PZD3) 01 F4h is transferred from the inverter to the master, that is the mapping from the example above (5.4.2) is still present.

*To start the inverter the Profibus state machine must be shifted in a correct way. This may be done in two steps. First the control word should be set to 04 06 (Enter Ready to switch-on state) and then to 04 7F (Enter Operating state). Refer to the state diagram in Figure 5-2.

18