# RISC-V-On-PYNQ - PL server connection error **URL:** \ **Category:** Support\ **Created:** [June 3, 2019, 2:41pm UTC](https://discuss.pynq.io/t/risc-v-on-pynq-pl-server-connection-error/158 "2019-06-03T14:41:33Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@Peter](https://discuss.pynq.io/u/Peter)\ **Post date:** [June 3, 2019, 2:41pm UTC](https://discuss.pynq.io/t/risc-v-on-pynq-pl-server-connection-error/158/1 "2019-06-03T14:41:33Z")
- PYNQ version: Release 2019\_02\_21 2382a55 - Board: PYNQ-Z1 - Vivado 2017.4 My goal is to implement a PicoRV32 RISC-V processor on my PYNQ board and I found the [RISC-V-On-PYNQ](https://github.com/drichmond/RISC-V-On-PYNQ) project on Github. Until notebook 4 [Packaging-An-Overlay](https://github.com/drichmond/RISC-V-On-PYNQ/blob/master/notebooks/tutorial/4-Packaging-An-Overlay.ipynb) everything went fine but instantiating the overlay leads to the following error: `ConnectionError: Could not connect to PL server` Has anybody else experienced these issues and does anyone know how to fix it? Thanks, Peter ## Full output: ```auto import sys sys.path.insert(0, '/home/xilinx/RISC-V-On-PYNQ/riscvonpynq/picorv32/') from tut.tutorial import TutorialOverlay overlay = TutorialOverlay("tutorial.bit") ``` ```auto /usr/local/lib/python3.6/dist-packages/pynq/overlay.py:299: UserWarning: Users will not get PARAMETERS / REGISTERS information through TCL files. HWH file is recommended. warnings.warn(message, UserWarning) --------------------------------------------------------------------------- ConnectionError Traceback (most recent call last) in () 4 from tut.tutorial import TutorialOverlay 5 ----> 6 overlay = TutorialOverlay("tutorial.bit") /usr/local/lib/python3.6/dist-packages/riscvonpynq/Overlay.py in __init__ (self, bitfile, **kwargs) 83 if(not os.path.isabs(bitfile)): 84 bitfile = os.path.join(self.__get_path(), bitfile) ---> 85 super(). __init__ (bitfile, **kwargs) 86 /usr/local/lib/python3.6/dist-packages/pynq/overlay.py in __init__ (self, bitfile_name, download, ignore_version) 313 314 if download: --> 315 self.download() 316 317 self. __doc__ = _build_docstring(self._ip_map._description, /usr/local/lib/python3.6/dist-packages/pynq/overlay.py in download(self, partial_bit) 377 Clocks.set_pl_clk(i) 378 --> 379 super().download() 380 PL.reset(self.parser) 381 else: /usr/local/lib/python3.6/dist-packages/pynq/pl.py in download(self) 1936 # use fpga manager to download bin 1937 if not self.partial: -> 1938 PL.shutdown() 1939 flag = '0' 1940 else: /usr/local/lib/python3.6/dist-packages/pynq/pl.py in shutdown(cls) 1456 1457 """ -> 1458 ip = cls.ip_dict 1459 for name, details in ip.items(): 1460 if details['type'] == 'xilinx.com:ip:pr_axi_shutdown_manager:1.0': /usr/local/lib/python3.6/dist-packages/pynq/pl.py in ip_dict(cls) 1295 1296 """ -> 1297 cls.client_request() 1298 cls.server_update() 1299 return cls._ip_dict /usr/local/lib/python3.6/dist-packages/pynq/pl.py in client_request(cls, address, key) 1417 except FileNotFoundError: 1418 raise ConnectionError( -> 1419 "Could not connect to PL server") from None 1420 cls._bitfile_name, cls._timestamp, \ 1421 cls._ip_dict, cls._gpio_dict, \ ConnectionError: Could not connect to PL server ``` ---
**Author:** ![rock](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/rock/32/32_2.png) [@rock](https://discuss.pynq.io/u/rock)\ **Post date:** [June 3, 2019, 5:36pm UTC](https://discuss.pynq.io/t/risc-v-on-pynq-pl-server-connection-error/158/2 "2019-06-03T17:36:07Z")
I suspect the reason is that you reinstalled pynq at some point and that failed or got interrupted. What about restarting the board? ---
**Author:** ![Peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@Peter](https://discuss.pynq.io/u/Peter)\ **Post date:** [June 4, 2019, 8:19am UTC](https://discuss.pynq.io/t/risc-v-on-pynq-pl-server-connection-error/158/3 "2019-06-04T08:19:01Z")
thanks, flashing the PYNQ 2.4 image again fixed the problem