Example of using Python to send Serial Interface Communications Protocol (SICP) commands to Philips Digital Signage. The newer versions have the backcronymn Serial/Ethernet Interface Communications Protocol.
This is not a full-featured library but rather a couple of scripts to turn the display on and off but should give anyone familar with Python a helpful start to controlling their signage.
I use a Raspberry Pi as a network status montitor connected to a Philips BDL4771V 47" Display. Rather than hunt for the remote, I wanted it to turn on and off automatically with the work day.
I noticed that it had a 9 pin serial port and dug into how to control it.
You may see two DB9 connectors -- one labeled RS232C In and the other labelled RS232C Out. We want the In connector. The other one is used to chain the next display in a wall of them so everything can be controlled by the same serial connection.
We only need three wires; transmit (TX), receive (RX), and ground (GND). This is a male connector which typically (but not always) indicated Data Terminal Equipment (DTE) as opposed to something like a dial-up modem which is Data Carrier Equipment (DCE). There are conflicting definitions for what DTE/DCE stand for but they are all pretty close.
The important thing to understand is that when you wire a DTE to a DCE using a 1-for-1 pintout, the DTE's transmit connects to the DCE's receive and the vice versa.
I'm going to assume you are using a common USB serial adapter.
But here we run into our first complication; the USB serial adapter you're using is also a male DTE connector. This means we need to fix a couple issues;
- The physical connectors don't fit as both are male pins.
- Pin 3 is Transmit on both.
- Pin 2 is Receive on both.
You need a combination gender adapter and Null Modem. You can buy these on Amazon as tiny wedges or you can get two female DB9 connectors and wire your own like so;
- Pin 5 to Pin 5
- Pin 3 to Pin 2
- Pin 2 to Pin 3
All the Philips appear to use the same port settings;
- 9600 baud
- 8 data bits
- no parity
- 1 stop bit
- flow control none
Oh boy. I was expecting something like the old AT modem controls where I could connect to the port and just type commands. Yeah no.
- SICP is a binary protocol.
- Commands are sent as packets with length and checksum bytes.
- There are multiple, incompatible versions. This bit me.
I'm including PDFs of all the versions I could find.
This is how I did it, your display may vary. It's possible the versions for each model are documented somewhere...
- Connected the display to a network with DCHP at least temporarily.
- Use the remote to open Menu, Configuration 1, Network Settings and note the IP address.
- While you're there, got to Advanced Option, and get the Monitor ID as you may need it. Probably 1.
- Open a web browser and go to http://[Step 2 IP Address]/html
- Log in as admin with the password 000000
- The first tab was Power Settings and the first box was SICP version. Mine was 1.7.
This thing did not want to give me anything to indicate I had a connection. I tried cold starts hoping it would send a boot message to the port like a like of gear -- nope. I sent packets based on a PDF for SICP version 1.99 I found on the Internet but nothing.
My set reported itself as SICP version 1.7. I kept hunting and eventually found a PDF for version 1.6 and finally got a reply;
b'\x05\x01\x00\x06\x02'Five bytes? According to the docs, this was "Command is well executed."*
So while most of the protocol versions worked on 6+ byte packets, mine wanted 5:
| Index | Byte Field | Description |
|---|---|---|
| 0 | Packet Length | Packet Size. This is the length of the entire packet, including this byte and the checksum |
| 1 | Monitor ID | This should be the number from step 3 above. |
| 2 | Command | Given as hex codes in the docs |
| 3+ | Possible arguments | Optional depending on the command |
| Final | Checksum | Sum of Exclusive OR'ing all preceding bytes in the packet |
For newer displays, there will be an additional Group field after the Monitor ID:
| Index | Byte Field | Description |
|---|---|---|
| 0 | Packet Length | Packet Size. This is the length of the entire packet, including this byte and the checksum |
| 1 | Monitor ID | This should be the number from step 3 above. |
| 2 | Group ID | I'm guessing this is for controlling part of a display matrix, i.e. giant TV wall |
| 3 | Command | Given as hex codes in the docs |
| 4+ | Possible arguments | Optional depending on the command |
| Final | Checksum | Sum of Exclusive OR'ing all preceding bytes in the packet |
Note: The PDFs use index 1 instead of index 0 but we're programmers here.
pySerial. I'm using Python 3 and installed mine with;
$ pip3 install pyserialI coded this using Python 3 and used the new f-string formatting introduced in Python 3.6 (which is so darn brilliant) for a couple lines. Sadly, version of Raspian on my Raspberry Pi was still on 3.5.3 so I had to edit them.
For newer sets you will probably need to add the Group. So line 45 in on.py and off.py becomes;
cmd = [MONITOR, GROUP, SET_POWER_STATE, PWR_OFF]Don't forget to define GROUP as whatever group you need, probably 0x00. The proper response in line 51 will probably change to;
if resp == b'\x06\x01\x00\x00\x06\x01':These are my best guesses as I don't have another set to test.